CarStack is a peer to peer marketplace where private individuals list, browse, and arrange the sale of used vehicles. This policy explains what we collect, why, who we share it with, and what control you have.
It covers the CarStack mobile app for iOS and Android, mycarstack.com, and related services (the "Service"), operated by CarStack from Florida.
CarStack is for adults only. You must confirm you are 18 or older to create an account, and we do not knowingly collect personal information from anyone under 18. If you believe a minor has an account, write to hello@mycarstack.com and we will delete it.
1. The short version
- We do not sell your personal information, and we do not share it for cross context behavioral advertising.
- We use no analytics or advertising SDK at all, and we do not track you across other apps or websites.
- We do not perform facial recognition or collect biometric identifiers.
- We never store your device's GPS position. Location about you is held at ZIP code level.
- Your content is not used to train anyone's general purpose AI models.
- You can delete your account, and everything tied to it, from inside the app.
2. Browsing without an account
You can browse listings and use Nitro before signing up. During a guest session we hold a temporary session identifier and the vehicles and conversations tied to it. If you create an account, that activity is migrated to your account. If you do not, it expires.
3. What we collect
Account
Email address, and phone number if you sign in by phone. Display name, profile photo, city and state, time zone, and your quiet hours setting. If you sign in with Google, we receive your email address and basic profile from Google, not your Google password.
Identity verification
Verification is optional and handled by Didit. Their SDK captures your ID document and performs a liveness check and face match on their systems, under their privacy policy. CarStack receives and stores only a session identifier and a pass or fail status. We never receive or store your ID images, document numbers, date of birth, or any biometric data.
Listings
VIN, license plate if you use plate lookup, year, make, model, trim, mileage, condition, colors, description, features and disclosures, asking price, number of keys, ownership status, and outstanding loan balance if you enter one. Photos and video of the vehicle. ZIP code, city, and state.
Location
- About you: city, state, and the coordinates of your ZIP code's center. That is ZIP level accuracy, not your position.
- About a listing: the ZIP code, plus coordinates deliberately rounded to two decimal places, roughly a 0.7 mile cell, so a listing never points at a driveway.
- During Deal Mode: if you use geofence arrival confirmation, your device checks whether you are inside the meeting spot's radius and reports only the result. We store that you arrived, the time, and whether it was confirmed by geofence or by tapping a button. Your coordinates are never sent to us or stored.
- Location you type into search or address autocomplete is used for that request and is not written to your profile.
We never collect background location.
Deals and bills of sale
When a sale reaches completion, we collect what a bill of sale requires: buyer and seller legal names, addresses, agreed price, final odometer reading, and each party's signature image. We generate the bill of sale PDF, store it in a private bucket, and email a copy to both parties. This is the most sensitive data in the Service and it is visible only to the two parties to that deal.
Messages, reports, and ratings
Conversations between buyers and sellers, reports you file, blocks you place, and post deal ratings. Ratings are double blind: neither side sees the other's rating until both are submitted or the window closes.
Nitro
Nitro is our AI assistant. It is software, not a person. We store your conversation history so it persists across devices. Photos you attach to a Nitro message go straight to the model and are never stored by us.
Payments
Listing and promoted story payments run through Stripe. Card numbers go to Stripe, never to us. We store one record per checkout attempt: amount, status, and the Stripe identifiers needed for refunds and accounting.
Device and usage
We do not use any analytics or advertising SDK. There is no third party tracker in the app, no advertising identifier, and no behavioral profile built for advertising.
What we do hold is what any app server necessarily records: our hosting provider logs the IP address, device type, app version, and timestamp of requests made to our servers, for security, abuse prevention, and debugging. We also store a push token per device install if you enable notifications.
4. AI features, and what we do not do
Nitro, listing descriptions, window sticker reading, listing insights, and Community Says all run on Anthropic's Claude models. Nitro can also run web searches through Anthropic's search tool to answer questions about a vehicle.
We do not perform face detection, face recognition, or any other biometric identification. Photo background removal is handled by PhotoRoom, which separates the vehicle from its surroundings. It does not identify people. Profile photos receive no processing at all. This is a deliberate design choice that keeps CarStack outside the biometric identifier rules in Illinois, Texas, and Washington.
Your content is not used to train general purpose AI models. Our AI vendors process your content to return a result to us and nothing more.
Recommendations. If you use Nitro, we may distill your conversations into a short summary of your vehicle preferences and rank recommendations against that summary. The summary is derived from your own conversations and is deleted with your account. This is personalization, not profiling that produces legal or similarly significant effects about you.
Blur license plates and house numbers in your photos if you would rather they were not public. The photo you publish is the photo everyone sees.
5. Why we use it
| Purpose | Examples |
|---|---|
| Run the Service | Accounts, listings, Stacks and swipe ranking, messaging, Garage, Deal Mode |
| Safety and fraud | Investigate reports, enforce blocks, detect fake listings, rate limit abuse |
| Personalization | Rank vehicles against your preferences and Stacks |
| Payments | Charge listing and promotion fees, issue refunds, keep tax records |
| Communication | Transactional email and push, and marketing only if you opt in |
| Legal | Comply with law, respond to lawful requests, defend claims |
6. Who we share with
Other users. Your public profile, listings, and stories are public. Messages go to the person you send them to. In a deal, the other party sees your legal name, address, and signature on the bill of sale.
Service providers, each contractually limited to providing its service to us:
| Vendor | What it does | What it receives |
|---|---|---|
| Supabase | Database, authentication, file storage | All stored account and listing data |
| Amazon Web Services | Underlying hosting, US West region | Encrypted storage and compute |
| Stripe | Payments | Payment details, email, amount |
| Didit | Identity verification | Your ID and selfie, directly from you |
| Anthropic | Claude models behind Nitro and AI features | Prompt content, including attached photos |
| PhotoRoom | Listing photo background removal | Listing photos |
| CarsXE | VIN decode, plate to VIN lookup, stock imagery | VIN or plate and state |
| NHTSA vPIC | Free government VIN decode fallback | VIN |
| Auto.dev | Plate lookup fallback | Plate and state |
| Google Maps Platform | ZIP geocoding, address autocomplete, nearby meeting spots | ZIP code or a coarse point, address text |
| YouTube | Finds a review video for a model year | Year, make, model as a search string |
| Expo | Push notification delivery | Push token and message content |
| Resend | Transactional email, including bills of sale | Email address and message content |
Legal and safety. Law enforcement or others when we believe in good faith that disclosure is required by law or necessary to investigate fraud or prevent harm.
Corporate transactions. An acquirer or successor, subject to this policy.
7. How long we keep it
We keep personal information only as long as it serves the purpose we collected it for, and then delete it or strip it of anything identifying.
In practice that means:
- Your account and everything tied to it is deleted when you delete your account. That includes your profile, listings, Stacks, Garage, Nitro conversation history, and preference summary.
- Records we are required to keep survive account deletion for as long as the law requires. That is completed deal records and bills of sale, which are transaction records, and any payment records once payments are live.
- Safety records survive account deletion, because a record that disappears when its subject deletes their account is not a safety record. This covers reports, blocks, and enforcement decisions.
- Messages stay visible to the other party in a conversation after you delete your account, because they are that person's record of the exchange too. Your name is removed from them.
- Server logs are held on a rolling basis by our hosting provider, currently up to 90 days.
- Caches keyed to a vehicle, a ZIP code, or a public place are not tied to you and are not personal information.
If you want to know how long we are holding something specific, email hello@mycarstack.com and we will tell you.
8. Your choices and rights
Anyone can:
- Edit their profile, listings, Garage, and Stacks in the app
- Delete their account under More, View Account, Delete Account. This removes your profile, listings, Stacks, Garage, Nitro history, and taste summary. It does not remove messages already delivered to other users, completed deal records we must keep for tax and legal reasons, or aggregated data that no longer identifies you.
- Change notification preferences per category. There are seven push categories (price drops, just listed, smart alerts, garage, listing updates, listing engagement, listing tips) and three email categories (price drops, just listed, offers and news), plus quiet hours. Transactional messages about your account and your deals continue regardless.
- Revoke location, camera, photo, and notification permissions in device settings
Residents of US states with comprehensive privacy laws (including California, Colorado, Connecticut, Virginia, Utah, Texas, Oregon, Montana, Delaware, Iowa, Nebraska, New Hampshire, New Jersey, Minnesota, Tennessee, Maryland, Indiana, Kentucky, and Rhode Island) may confirm whether we process your data, get a copy, correct it, delete it, get a portable copy, and opt out of targeted advertising, sale, and consequential profiling. We do none of those three, so there is nothing to opt out of, but the request path exists. If we deny a request we will tell you how to appeal, and we answer appeals within 45 days.
We honor the Global Privacy Control where state law requires it.
To exercise a right, email hello@mycarstack.com. We respond within 45 days and may extend once by 45 days for complex requests. We verify you through your account. An authorized agent may act for you with written permission. We will never charge you or degrade your service for exercising a right.
9. Security
Every table in our database enforces row level security, so one user's data is not reachable by another. Data is encrypted in transit and at rest. Bills of sale, signatures, and original uploaded media sit in private buckets that require a signed, expiring URL. Payment webhooks are signature verified. Service credentials are never exposed to the app.
No system is perfectly secure. If a breach affects your personal information, Fla. Stat. § 501.171 requires us to notify you no later than 30 days after we determine a breach occurred, to notify the Florida Department of Legal Affairs within the same 30 days if 500 or more Florida residents are affected, and to notify nationwide consumer reporting agencies if more than 1,000 individuals are affected. We will meet those obligations and any others that apply.
10. Other people's information
If someone else appears in your photos, or you upload documents naming another person, you are responsible for having the right to share that. Do not upload anyone's identity documents, insurance cards, or financial records.
11. Where your data lives
CarStack operates in the United States. Data is stored with Supabase on Amazon Web Services infrastructure in the US West region. If we make the Service available outside the United States, we will update this policy before doing so.
12. Changes
We post changes here and update the effective date. For material changes we give notice in the app or by email before they take effect.
13. Contact
Email: hello@mycarstack.com
Florida residents may also contact the Florida Attorney General. California residents may contact the California Privacy Protection Agency.