except that i researched chevy thoroughly and decided that it sucked. now i have to go and purge what google thinks it knows about me. and theoretically repeat this process for every other ad network, but this is neither possible nor practical.
Not everyone is going to buy Chevy but almost everyone is going to research Chevy. The role of Chevy ads being shown to everyone plays a role in this. So a Chevy ad still is “relevant” even on an ice cream site.
no thanks.
That's how tracking ads (don't) work. You usually get ads for things you just brought (or decided not to), hoping that you didn't actually buy it yet or will buy more than once, and the medium can intermediate the transaction.
Time for a re-decision. Expect to see those ads for years to come. How does a 2019 cherry-red Corvette sound?