What about adding material to both the inside and the outside? It would be twice as much work, but just a thought to give a third option Inner outer both inner and outer Thing is, they got to get the modification PERFECT-It's got to be HARD to do! I'd like to see how they do it. If I remember correctly, NASCAR is 10 x 15, and they have reasons for it. Kind of make you think about the custom larger wheels like 18 - 20 inches, while they look cool, they have a harder ride and if you hit a pothole or any road hazard, it is easier for the rim to bend. Personally, I care more about how the car handles than how the rims look so I will stick with 15 inch rims. They work at 190mph on NASCAR and on my Z28 with a 155 topend 1:1 Besides, every thief and his dog are trying to get their hands on those pretty boy 18 & 20 inch rims!