There were both rear and mid-engined R5 turbos, as I recall. As an aside, the year the Bugatti Royales were all at Pebble Beach, the Ferrari Owners club held a "run what ya brung" time trial for it's members the day after the Historics. They brung some pretty interesting stuff. An R5 took FTD, despite the fact there were some serious Ferraris and Cobras out there. John