It depends if you want it to be a fun challenge or if you wan't the fastest, the fastest FR cars are the Castrol Supra GT, Viper GTS-R or fully tuned GTS / RT-10, Cerbera LM or a full tuned Nismo GT-R LM road car. Fun ones are slightly modded Supra's, RX-7's and anything thats simmilar in performance to the AI cars.