Hmm, well, I definitely have some things to learn. Maybe just need to start making wads of cash. For the moment, I don't have enough money to buy all the best non- or low-PI-increasing upgrades (such as brakes, suspension, clutch, etc.). And there are so many parts available that it's kind of overwhelming. So I've been just doing the auto upgrade, which seems to do a mix of power, handling, and weight reduction upgrades. Probably not the most effective for now. I mean, I placed dead last by a wide margin in our first race, and only avoided repeating that result on the second one because two guys behind me crashed.
Meanwhile, I'm also using an auto transmission and the rewind feature gets some use as well. I've been racing with the line off for single player, but in multiplayer I keep it on. Perhaps once I learn all the tracks I'll be able to turn it off all the time and not have to use rewind.
I do enjoy the game, but I need a lot more time to build up cash and get comfortable with it. It's quite different from 2 and unlike some of you guys, I am not a very hardcore racer. At this point I am not even sure if I prefer Shift or FM3. FM3 has a better framerate, less dodgy driving mechanics, a better interface, and a huge variety of cars, but Shift is more exciting and fun in single player.