I had 9mil, was going to do a few races to get the Ferrari but felt like a waste. The GT Formula 1 was only 4.6 mil. I have about 6.8 mil right now, if I can sell the GT Formula 1 for ~2mil, I think I can get up to 10mil in a few races.

edit, just been informed that you CANNOT sell the GT Formula 1 car.