I have a 2001 GT with just the basic bolt on upgrades. The car only has 7000 miles on it and I am having a problem with the transmission. When you are running hard and try to go into third it "locks" you out. Or sometimes it will let you in, but grinds badly. I have taken it to the dealership to get fixed, which took 30 days, it is doing it again. I have had another guy drive it and it happened to him to. Any suggestions?