Ok, let's recap here, cause maybe haven't given enough info
 
like I said, 9800 gt, Logitech force gt steering wheel, Updated drivers and no overclocking. 
 
Game freezes, glitches appear and system goes slow & nuts
 
 
Same with other car-games, but not with fallout 3, crysis and so on.
 
no temp problems.
Windows XP SP3
tried playing with and without logitech wheel and same crashes.
have a 7600gs now borrowed and works fine
 
maybe Point of view 9800 gt crap¿?¿