https://www.theregister.co.uk/2018/02/15/orbital_calculations_for_elon_musks_tesla_roadster/

Explaining why he used his Tesla roadster as the test mass on his Falcon Heavy launch, Elon Musk remarked that he liked the idea of it orbiting for a billion years.

If the car endures, a bunch of astroboffins from Canada and the Czech Republic reckon it's going to last just a mere few tens of millions of years.