???On about lap 7 on the long straight all my controls, steering throttle and brake stopped working spinning me down the track.
Exactly what I was plagued with in all of my initial AC races, and very frustrating I know. In my case it turned out to be iTunes kicking in to automatically look for updates, every Wednesday evening, slap in the middle of our races.. Disabled that and not had a problem since. Look in event viewer which may give you a clue as to the culprit, but as Mark says try and disable as many potential popups/auto-updaters as you can.
Alt-tabbing out and back into the game gets you your controls back by the way, but that's not much use when you've already hit something..
