The other car(Cossie) has to be insured , obviously for you to be on the road driving it, why you ask, cause what if u park it up on a hill, the handbrake lets go and it rolls down into another car aint your fault cause you werent driving it so who is it down to......the owner of the cars policy itself , and your "lesser" car obviously needs to be insured by you to get the policy to drive the fookin Cossie, and what a load of crap about it needing to be less powerfull , its the policy not the car that counts mate, that said less n less companies are doing it now and within 2-3 years u wont be allowed to do this sort of thing, but who cares Ive built up nearly 4 yrs no claims so I`ll be putting the Cossie in my own name next yr cause my little bro(18) wants an M3 Convertible and needs to use my dads name on the policy and he cant have 2 policys now can he