This caption from Safety Fast, January 1983, is apparently in error. In Safety Fast, October 1985, another note appeared indicating this car is most likely not YD1 502. Additional conjecture implies that this car may actually be a few serial numbers earlier, being one of the three prototype Twin Cams.

DVLA still show's it as being registered (but this number may or may not be the same car) .

Date of Liability 01 12 2005
Date of First Registration 11 12 1981
Date of Last V5 Issue 06 10 2003
Year of Manufacture 1958
Cylinder Capacity (cc) 1600CC
CO2 Emissions Not Available
Fuel Type Petrol
Export Marker Not Applicable
Vehicle Status Licence Not Due
Vehicle Colour RED

Also review notes at: TC107-502.htm - TC108-500.htm - TC108-500A.htm

2 RHD and 1 LHD prototype cars were supposedly built. ORX885 is the other RHD car and it bears car number 500. PJB.147 appears in lots of promos for the Twin Cam and was black with black.