Originally Posted by jdsto

sounds like a huge amount of money to destroy the handling of the car. The torsional rigidity of the car comes from the roof. Simplistically the roof and the floor work together to tie the two ends of the car together and make them work together. Cut the roof out and car will twist itself apart when you apply power or try and corner. Think of a weights on two ends of a thin piece of wood the wood will twist and flex very easy. This is why you have only seen this on show cars as the cars are likely not driveable anymore.