Go over to XPF and ask Rincewind (Nic Fasci) he will know. Not sure about this one but there were a small number of car used for different reasons, chassie, engine, speed, brakes etc. Nic was one of the engineers involved in pre-production testing taking the V8's down to Spain etc for blats. Must have been a gutty job. It will have a low Vin number. Be interesting to know what it is.