Finally, Murray relented and agreed to modify the F1 into a racing car, agreeing to build several chassis for competition in the 1995 season. An unused F1 chassis which was meant to become #019 was taken by McLaren and modified by the company as a developmental prototype. Because of the similarity to a race car, extensive modification was not needed to actually turn the F1 into a racing car. Bodywork modification saw the addition of various cooling ducts, most noticeably a large one in the center of the nose and two placed in the location of the storage lockers on the side of the car. A large adjustable fixed wing was added to the rear of the car. Even the 1995 versions of F1 GTR generated enough downforce to run along the ceiling at 100 mph. The interior was stripped of all luxuries and given a full racing cage. Carbon brakes replaced the stock units. Because of the rules at the time, the BMW S70 V12 engine was required to use an air restrictor to limit power output to around , making the racing car less powerful than the road car, yet faster and more nimble due to a lowered overall weight. Features such as the central seating position, Butterfly doors, and even the standard gearbox were retained. McLaren co-ordinated a 24-hour test at Magny-Cours to find weaknesses in the car and develop upgrades to supply to the teams.