Development Blog, Grand Prix 1973 Grand Prix BT42 Development: Day 4: Rear Suspension and Wing Posted on April 1, 2021April 14, 2021 by admin 01 Apr Day 4: Today we’ve finished the rear of the car, which includes suspension, rear wing, rainlight, radiators and rear brakes. Next stop: rims and tyres. Grand Prix BT42 Development: DFV Sound Grand Prix BT42 Development: Day 5: Wheels and Exterior details