he will have every racer drive every racetrack in every possible manner with every type of car imaginable.  then he will record each of these races at every possible angle.  lastly he will put these things onto one perfect virtual racing game the world will cherish until the end of time.

Basically this,  plus add in all of the Nascar, Indy, F1 and Lemans race tracks in the world, both old and new.

gt6 cars had embedded consoles on which you can play gt7 on the rear seats. and there would be a printer addon in gt6's case to print fully working real life sized cars

So basically it would have to be a full immersion virtual reality simulator or real life.

The real question is what will happen to the GT series once Kazunori Yamauchi retires? He is 43 at this point, the development cycles are getting longer. GT6 is not going to be released before the next console cycle starts as Sony will not make the some mistake twice (i could be wrong) with releasing their biggest franchise title more than 3 years after the console has hit the market.

GT6 will probably be the most realistic and best looking game ever to be released for a console. 

holodecks

The final game would be on 10 dual-layered Blu-Rays.

make cars that drive better then the real ones. 10 yrs only because he (like Fumito Ueda) would never finish the game if they didn't have a release yr or date.

You do realize they have already started to work on GT6, which makes it a good possibility it will be for the PS3.

nothing restricting him? Assuming he lives by then, everything. Literally.