I'd say some Crown Victoria is probably a good candidate. In police versions they vary a lot in painting, so the NYC yellow taxi must outnumber them.

The single car that appeared in the most movies/series may be the Rolls-Royce of this member: https://www.imcdb.org/profile.php?id=ertyuio

Hi,

It's easy to find what car has the most movie appearances, but I'm looking for a car with many movie appearances that is visually similar across many movies. So for example a black Ford Crown Victoria, which doesn't seem to change visually from year to year...any leads?