2. The wheel opening was huge! The 33-inch Mickey Thompson Baja ATZ's look dinky inside. Also note the amount of 4Runner body visible inside the fiberglass wheel opening. The wheel opening size differences were remedied with a two-front approach. The Fiberwerx wheel opening was shrunk, while the 4Runner wheel opening was stretched. The goal was for the 'glass to flow with the body lines, and for a 35-inch tire to fit even at full bump.