i've been playing racing games on my ps2 for years......gt3, gt4, F1 , racing trucks, nfs, you name it.....out of all of them gt4 was the top game, but then i stumbled across Toca3.
Toca3 has one of the best racing "engines" i've ever played, the physics are realistic, damage is realistic (softer shocks damage easier....if you break a shock the tire also wears pre-maturley)....
a lack of different cars is made up by the vastness of different types/eras of racing.
there are also F1 cars from the early days to senna to modern, also the computer difficulty is adjustable up to 110% and comp controlled cars are inteligent and won't ram you for no reason like other games........
the best one out there.....if you like good racing action it's a must have
also online compatible.
a review
http://www.totalvideogames.com/articles/TOCA_Race_Driver_3_Review_9458_4607_0_0_10_0.htm
on the right in this link are some video clips of spa and such.