I can get a deal on tt2. Now my question is what offset do i need to fit 17x11 out back and 17x9.5 up front. What tire size will i need and what modifications do i need to the car to make them fit.

 

same question i have but i want 18's

 

both sizes 17 and 18 have the same in backspacing.
the 18x10 is 7 1/4 inch backspacing and will work front and rear
and the 17x9.5 is 7 inches and 17x11 is 7 3/4inches. the rear will go 315 for the 11 and the front 275.
on the 18 i wouldnt go any wider the 295 and i put 275 on the front but have seen 295, although i dont know if it would rub but i know 275 doesnt.