The two-door GT originally planned by Jaguar finally went into production in 1975, though it had first been unveiled in 1973. It was not nearly as sporty as the initial blueprint had intended - on the so-called short wheelbase, they were only 50 lb lighter than their four-door counterparts, and little more aerodynamic. The XJ6C and XJ12C coupes were effectively two-door XJ saloon rather than sports cars in their own right, to bridge the gap between the E-Type - finally discontinued that year - and the XJ-S. Or they were meant to: in practice, the two-door body was not as refined as it should have been, due to problems engineering the roof structure, window design and the sealing. Jaguar had to make a huge effort to quell wind noise, and ended up saving money by fitting vinyl roofs to cover up the messy welding beneath. Just 6505 XJ6Cs and 1873 XJ12Cs were made before the range was discontinued in 1977. They were particularly popular amongst the Americans, who liked the XJ12C's black vinyl roof - very Seventies. However, the range was now beginning to suffer from the lack of investment under British Leyland, and the XJ was getting a reputation for a shoddy finish and quality not quite befitting a luxury car; the electrics, by Lucas, were especially problematic. Dymock also comments that although Jaguar had used fuel injection in its racing cars, "making it work as reliably as carburetors was a formidable task".