You can put the game in coaching mode or whatever it's called and then run it at like 8x the normal speed. IIRC you can freely switch between driving and coaching mode if you select the right thing before the race. That way you can drive the first few laps, then switch to coaching mode, up the speed to 8x and just tell your car to pit every now and then. This obviously doesn't take much skill but then neither does getting the best car and the game and crushing all the other cars on the track (but as you said it's the only way to be safe in such a long race).