why dint u just measure it like any normal bod ?
Oh, and just because it fits in one ncp, doesn't mean it will fit in all of them as they is all different. Done a fair bit of work in various ncp's , and me freelander goes in all of them, c/w roof rails. In some of them, I can still get in, even with roof bars a set of triples, and pair of 8 treads on top, held down with ladder clamps. But some of them are much lower, either due to their construction, or a later refurbishment which brings all the services (lighting, trunking, sprinklers, pa, fire detection and so on) down off the slab.
Speak to the manager/operative of the car park concerned. Lots are higher on the ground floor level, and keep a few spaces back on the ground for higher vehicles (transits etc), and will let you park there. However, depending on where it is and how you feel about the manager/operative, it might be polite to offer an incentive (i.e. cash), which should help you secure a space in future.