My calculations for the rear is 14.5" wide x 46" long
The fronts, 15.75" at the square front edge, 23.75" at the widest point where they bolt to the cargo bins, 55" long on the outside edge, 51.5" on the inside edge.
Each car is going to need approximately 17ft of 24" wide 3/8" thick conveyor. Example this 3/8" wide 24" x 40ft will yield enough for 2 cars plus some extra. $321, including shipping for 214lbs.