I have found a car on ebay - but it has a "Competition Diaphragm
Clutch"

can you use this in a road car? can you replace it easily? what
difference does it make in driving?

How easy would it be to "detune" a race tuned engine?

I'm interested in entering a "rally" car in the non competition part
of the LEJOG this comming year for charity - there is a rally car on
ebay at the moment, but it's race spec and "not suitable for road use"
due to the above.

Any help would be appreciated

Cheers