ok i've got it also, and my first impressions were, oh my god this is absolutely shite, do not trust the automatic graphics and control calibration it made the game look and feel terrible.
i've got a 750mhz Athlon with Geforce 2 MX 128mb RAM and at 800*600 res can run most things medium or high apart from bump mapping and reflections so it looks pretty good. the controls are @!#$ it took me 40 mins of experimenting to get it right but once I did I finally started to enjoy the game.
I'm not sure on the physics, the car feels like its got slightly too much grip, like on-rails as its been said before, as LS says it does spin more easily but i've found it only spins if you take too much kurb at which point you loose the car
very suddenly apart from that its actually quite difficult to loose the car unless you get on the throttle to quickly.
The people who have said that they've played it for 5 minutes then deleted will be mising out quite a bit because my first impression was that it was terrible but its definetely grown on me and I think its pretty good now although not the huge leep it should be, its basically the game Grand prix 3 should have been.
The mechanics are great though but the launch control is much better in F1 2002, in gp4 you don;t operate it manually it just means you can floor the throttle without spinning.