1. Alfa GT - it'll NEVER spin on you, it's Italian and it can pull the most speed through the corners. Most of the time it looks like it will understeer but actually it doesn't, you just have to learn to trust it
2. Aston V8 Vantage, Audi RS4, Nissan Skyline, Jaguar XKR, Lambo Gallardo SE, Lambo Murcielago, Shelby Daytona Coupe are all easy to drive and hard to spin. McLaren F1, Koenigsegg, Jaguar XJ220 have really high top speeds. Mustang GT is quick accelerating for its class, while the Ford GT is quick accelerating full stop (but it's still Class B though, so it'll never compare with an Enzo)
3. Just go to the showroom, pick the car, the colour, rims and interior colour and you're ready to go. You can get it tuned at the tuning shops once you find them.
4. The com will do it for you if you select and online profile when registring for the game.
5. Hard disk space: 8GB required