just beat the game and loved it. for those with a pc, i'd recommend the freeride mod. you get to freeroam after beating the game and it gives you all 46 cars. you can also choose the weather you want. to go with this, i downloaded the real car names mod. also, i got a mod (all from the mafiascene link above ^^^) that makes the women in joe's apartment naked (to start chapter 13).
I just finished this. Spoiler You can't do anything once you beat it? And no finishing sequence other than Joe being driven off? Weak ending no, for various reasons? I don't mind a dark ending, but a 45 second ending with an abrupt stop...wasn't happy about that.