I understand being scrappy and all but a cheap used car doesn't have to be a car that constantly breaks down and has lots of trouble. I personally use a small used car (1999, my previous one was a 1991) that I keep in good condition but rent something spacious when going on vacation with the family. But it doesn't seem like anything special.
Indeed, I think that keeping a poorly maintained car is often a clear case of being penny-wise but pound-foolish.
I would even venture to assert that this is almost always the case if one values ones time above a certain amount, though I've never estimated what that would be[1]. The aspect which is risky, and therefore perhaps appropriate to a startup, is that the car might fail at a particularly inopportune time, costing reputation or good will.
[1] I did, however, estimate such a value for driving 65mph instead of 75mph, spurred by a radio ad extolling the fuel-saving benefits of a lower speed. Based on the fuel savings and price at the time (also around $3/G), it was under $15/hr. If anything, it was remarkably revealing of the, unsurprising, attitude in government of the value of citizens' time.
Maybe there is a back story I am missing here.