The Punto is hardly the most stylish car in the game, it's sloped rear begs to be shunted so that its looks might be improved somehow. The Fiat badge is the most distinctive marking I can describe, so if you're confused which car is the Punto - look for the blue badge.
Aside from the aesthetics, what you'll notice is that the Punto is actually quite nippy - it has instantly pleasing acceleration and its handling is good enough for you to weave through traffic. It soon reaches a lowly max speed however, and it's not the sort of car that hard men like Frank and Mark want to be seen driving. This is quite commonplace and found all over London.