The X1r should work with the NAVI portion and if you have a N2, N1, N3 hide away which houses the tuner it should work. The only thing you will probably have to do is force write your 50 or 60 series discs in the service menu. Maybe not even that.
I'd give it working more than a 80% chance since the tuner isn't in the head, and when you force write a US model it get's the language data from the disc and references ALL major EU languages. Put a US disc in and it only has English US, French, and Spanish.
The boot software has German in there, so it's almost like they used a universal boot for everywhere but asian countrys and the MAIN difference is what is on the MAP discs and the hide away.
The service manuals even reference the Europe manuals.
Also in the hide away is the MICON that controls the IP BUS (XM, IPOD, etc.) so on a EU hide away, there won't be XM support since they don't have XM.
Chao!