The only car you'll want to use for Time Trials is the 330 P4. This car will make ALL the Time Trials ridiculously easy to the point you'll beat them all on the first lap with plenty of time to spare. The 330 P4 costs 90000 credits, so if you don't have enough I'd advise you to go and work on one of the other modes in the game first to earn enough to afford it.
The setup I used was Arcade, and my assists were Automatic transmission and SC Strength, TC Strength and ABS Strength were all set to Max.
There are 6 European circuits and they are -
GB Raceway
Spa
Rhine Speedway
Le Castellet
Eifel
Riviera
The times you're required to beat are displayed at the bottom of the loading screen before the trial begins.
I'd wish you good luck but seriously they're so easy with the 330 P4 that you won't need it!