I like to set up a private match, me v 16 AI drivers on indianapolis motor speedway and i drive the wrong way so i can crash into the computer controlled cars. I went so high i could see the outer areas of the level were there was alot of unfinished scenery that you would not normally see. Its understandable beause the devs probably dident think anyone would get that high 
I wish there was a reward or prize for thid it is not easy at all.
Message to the developers
I would like the following things added to forza 5, tv and film car pack featuring cars from famous films or tv like the glowing green car from automan, night riders car, A Team van back to the future delorean, the pink panthers car. Also add super trucks and nascars. Bring back create a race team to forza 5 that was in forza 4. Also at E3 Dan greenawalt said that everything on the tracks in forza 5 like trees ect will growv and change regulary because of the cloud but i have not noticed any changes.
DONT TRY THIS IN ONLINE RACES IT IS STUPID, ANNYOING AND YOU WILL JUST GHOST THROUGH OTHER CARS.