In Columbo's case it gave him a modifier, though: you never saw him engage in ranged combat but he did gain points in charisma and wisdom. There's a lot to be said for being scruffy.
Talking of which, ISTR he drove a Buick Skylark for a bit. I borrowed one that was even more disreputable-looking than his. It was awesome from that point of view, as well as its sort of "anti-Tardis effect" where it was very much smaller on the inside than the outside, but overall it was an incredibly horrible car.