Not to speak for Lubo, but it would've been the same reason i was considering that size and combo...
width wins with racing
If you want to get down to the facts, call Eddy. He's awesome and will get you correct. He knows the 1 series, and can point you towards other 1 owners who have tried similar things.
If this is a looks and street setup only, square up 245's or 235's. If you want the best cornering you can have, get camber plates and throw 255's up front and roll that rear.
I opted for 18s to get the most rear rubber i could and found a great deal on some 275/35/18s. APEX knows what they're doing and gave us a perfect offset rear wheel where that 275 literally fits with no modifications.