Excellent, another memeber and another roadster.
On your legal issue - if it was advertised as having cruise then you certainly have a claim. If it is a brand new car then obviously the value of the cruise control can be worked out pretty easily by just looking what Nissan charge for it as an optional extra on their range.
If it's second hand then it becomes more difficult to ascertain the value of cruise. Basically you have to work out how much more a car with cruise is worth over a car that hasn't got it, the difference being the claim. It'll be a few hundred quid so worth claiming.
Obviously going to court's a pain so have a reasonable chat and see where it goes. You could always settle for free servcing etc so that his actual outlay is reduced but the value to you is still there - just an idea.
Can you tell my wife's a partner in a law firm ?
Hope it helps