The rear seat area is intentionally arranged to ease rollcage fabrication. The rectangular cover panel over the rear axle hump is not OE Challenger architecture. Rather, the formed metal cover is provided to allow clearance for a Dana 60 live axle. Temporary rivets secure the cover for easy removal during race chassis fabrication. The open area between the interior and trunk compartment must be closed for NHRA compliance. All transmission tunnel, floor pan, and other chassis modifications to the unibody are performed by Roush personnel in Livonia, Michigan.