Privacy

Last updated 14 October 2026

Car Price Tracker is a personal project run by Ben Rometsch in the UK. It records the asking prices of second-hand cars over time and publishes that history on this website. This page explains what the browser extension and the website collect, and what happens to it.

The browser extension

Where it runs

Only on autotrader.co.uk and carandclassic.com. It does nothing on any other website, and it only ever sends data to carpricetracker.com.

What it sends

When you open a car listing on either site, it sends the details the seller published:

• make, model, trim, year, mileage, engine size and asking price;
• the registration plate, if the listing shows one;
• the listing's web address, with any query string removed, and the address of its main photo;
• for Car & Classic listings, the seller's description.

On a search results page it sends the same details for every car in the results. On a Car & Classic search page it also sends the address of the search, so that we can keep following it and pick up the cars on its other pages. That address holds the search's filters, such as make, model, price, year or the country the cars are in. If you've typed a place into the site's location filter, that part is removed before it's sent.

Each request also carries the extension's version number. As with any request to any website, our server sees the IP address it came from.

What it doesn't send

• anything from websites other than the two above;
• your postcode or location: AutoTrader puts your postcode into its addresses, so the extension strips those before sending and doesn't send AutoTrader search addresses at all, and a place typed into a Car & Classic search is removed too;
• details of a listing that we don't use, such as where the car is;
• your AutoTrader or Car & Classic account details, messages or saved searches;
• your cookies or browsing history;
• anything that identifies you. Listings arrive without a name or account attached, so we don't know who sent them.

What happens to it

The listing details become part of the public price history on this website, which is the point of the extension: every listing anyone views helps build a picture of what cars are worth. Because we don't know who sent a listing, there is nothing about you in that history.

On your device

The extension remembers the last car it saved, so its toolbar button can link straight to it. When you open that button, it asks this website whether a newer version of the extension exists, sending only its own version number.

The website

Accounts

You can use the site without an account. If you create one, we store your email address, a securely hashed password, the cars you star, and your email alert settings. We use your email address only to send the alerts you've asked for: price drops, sold cars and the weekly summary. Every alert email has a link to switch it off.

Cookies

• sessionid and csrftoken: keep you signed in and protect forms from forgery;
• dismissed_announcement and hide_how_it_works: remember that you closed a notice;
• Google Analytics (_ga and similar): count visits and see which pages are used.

Other services

• Google Analytics (Google) receives information about your visits to this website. It isn't used by the extension.
• Brevo delivers our emails, so it handles your email address when we send you an alert.
• Some page scripts load from the public code libraries unpkg.com and cdn.jsdelivr.net, which see your IP address when they do.

Like every web server, ours records the IP address and the page requested for each visit.

Your choices

• Remove the extension at any time from your browser's extensions page. It leaves nothing behind.
• Switch off any email alert from the link in that email.
• To delete your account and everything stored with it, email us from the address you signed up with.

Contact

Questions about this page or your data: [email protected].

If what we collect changes, this page will change first.