At first glance, the FR500 interior doesn’t seem that far from the showroom floor. The standard ’99 Mustang dark charcoal interior is accented with two-tone leather seats with added bolstering, a white-face instrument cluster, a leather-wrapped steering wheel, and a JBL sound system. What doesn’t hit you right away is this cozy cockpit is inside a powerful, track-worthy Mustang. About the only thing the Ford Racing guys are going to tweak inside the car is the lateral support of the seats.