So Obviously they are 64 missions on total. They start off easy and gradually get harder. I often get stuck on the Rival race ones, Especially the Amigo V Ai Ai one!
So if you have already completed all the mission but not yet achieved AAA on each mission you'll know they are some missions that sometimes make you wanna throw your xbox out the windows from time to time. Some BIG examples are; Mission 42: Monkey Trouble, Mission 64: Finale and ermm. The Horrible Cup, or the Horror cup or something. I didn't have any trouble with this i just heard from many people that it's hard because of the racer your stuck with. Don't blame them really as the racer has such bad handling on the car :\ I must of got lucky.
On the Amigo Vs Ai Ai Rival race you'll notice you can actually use weapons against the opponent making it easier? Well if the track wasn't such an awkward i'd think it would be easier too? Only tip i can give for this is to time Drifting perfectly round corners, it's never too early before a corner to start drifting. Also when you get towards the end and you'll notice you got to do tight 180Degree Drifts, to sucessfully do some a tight drift you got to let go of the Gas as you turn the corner, as your still drifting you can still turbo boost once round the corners, so your not losing speed at all. I have noticed that on the last 180Degree turn Ai Ai crashes into the wall near enough all the time, because of this i was able to get AAA easily.
I will post mission 42 and mission 64 video on here.
Here is the guy's channel on Youtube, I think he has a video for some other missions on Sonic & Sega All-Star Racing just in case your having trouble with any other mission.http://www.youtube.com/user/Hoorndragon666
Thanks :) Any problems please comment :)