Porsche is developing a halo supercar called the S1 featuring a flat-eight engine, marking the automaker's first flat-eight road car. The vehicle, expected to start around $600,000, represents a return to Porsche's racing heritage with the engine configuration, which the company previously tested in a modified Cayman prototype.
The Jaguar XJ220 was an unofficial project that became the world's fastest production car at 217 mph, debuting at the 1988 British Motor Show. Originally planned as a Group B racer with a V12, it was produced as a road car priced at £415,554, but disappointing sales during the early 1990s recession and the lack of promised V12 engine led to cancellations. Despite commercial struggles, the XJ220's aluminum honeycomb chassis and turbocharged engine innovations influenced subsequent Jaguar models.