I have no knowledge of the amount of carpet necessary to do the inside of a GT 40, but my background was 43 years in the carpet industry. Ozite was known for manufacturing indoor/outdoor carpet. It was low/flat and tightly constructed, so it was durable, and dirt would not get buried in a deep knap. It was also manufactured in 6 ft. and 12 ft. rolls, versus the industry standard of 12 ft. only. If you are looking for something of a higher quality, richer look, you’ll probably want to investigate woven wool carpets. A woven (Wilton) velvet or tight loop is probably what’s used in luxury sports cars and sedans like Rolls Royce, Bentleys, etc., most of these are made in Europe or Australia where the wool is less expensive, so they are manufactured in 4 meter wide (13’2” rolls) versus American 12’0” wide rolls.