But that secretive development process, almost entirely done by Tom Walkinshaw's TWR team, would eventually lead to one of the best looking, most sought after and beloved cars Jaguar would ever run.
The XJR-15, in both road and racing guises, was perhaps the ultimate road-going expression of what Jaguar and TWR had learned on the race track with the XJR programme. So noisy was the car inside that a comms system was added so that driver and passenger could actually speak to each other. So popular was the race series that the final had a multi-million pound prize fund and rumours swirled about fixing the result.
At the 78th Goodwood Members' Meeting we celebrated this extraorindary car with a brilliant demo on track of both road and race versions. We spoke to designer Peter Stevens (of McLaren F1 fame) to see what he thought of his amazing creation.