I want to autocross this puppy on either KUMHO MXs or V710s and they both come in 245/45 ZR17s for 8" rims!!

Has anyone tried 245/45 ZR17s on a MKV GTI or Rabbit? The dude at Tire Rack talked me out of the 225s and said they knew the 235s would fit better on 8" rims.....but I want to try the 245s since I can get the V710s in that size but not in 235s. I can't wait to see how these look with O.Z. Ultraleggeras!