My exact car is in the game, the 2008 Fiat 500 1.2 8V Lounge. In the game, however, it's listed as a 1.2 8V SS Lounge. The SS is only available on the Abarth 500!
Exterior
Anyway more to the point, the model in the game is very accurate. It's a little too tall to be 100% accurate, but the lights, body parts etc. are near perfect. The car in the game has added side rubbing strips, reverse sensors and chrome mirrors which are optional extras on the 500 but again they are very accurate.
Interior
Faultless from what I've seen so far. The game accurately recreates the rev counter and trip computer, as well as the radio unit and leather wheel. The interior is based upon on the Ivory interior option instead of the black, but being the Lounge model this makes sense. Another good feature is that the dashboard strip changes colour when you change the exterior colour, just like when you spec up the real car.
Wheels
Spot on. They could do with being more 'metallic' but even the chrome center caps are present.
Performance & Handling
Again, very accurate. The car loves being revved and the engine always feels eager. It turns in fairly sharply, just like the real thing, but then you get a large amount of body roll and a fun level of grip for such a small, rolly car.