It's funny how different perceptions seem to be. I don't remember finding Mission 34 that difficult at all. I recall a run with getting a rear wheel on the grass, doing a 360, and beating it.
On the other hand, I never managed to bring up the power to try and beat 2 of the gold times for the Vettel Challenge in GT5. I did manage to get the gold for the Tomahawk, but in my opinion both the Vettel and the Tomahawk have nothing to do with driving at all. It's just trying to stay on track somewhere towards the middle, because tiny movements of the wheel will launch you into a barrier. Of course the theoretical best is far below the gold time, because if you manage to string together 73 perfect reactions, you can go through every corner at almost twice the speed. If the likelihood of doing that for you is somewhere in the area of 10% though, it's rather unlikely to ever happen though.
Or maybe I'm just too old for it.