The F090/s race car would be one of the best cars in the game.
You could use it for a lot of the endurance races and race it in either Beginner, Amatuer, and Proffesional leagues which would give you a good boost in completing the game.
Another good car would be the Escudo Pikes Peak Version. It cant go over 207mph but it is effective in many ways.
You can use it to do the Rally Events and it works good on the Super Speedway 150 miles in Endurance Races.
I hope I helped you out.
More tricks, tips and cheats for this game are right here - Gran Turismo 3: A-Spec cheats
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