No prob. Yeah it was something I was interested in since the ETK schematic for the steering wheel is the same one used for the X5 and X3. There are some cases when the p/n's are interchangeable, however many are not. What I do know for certain is that:
1. The wood is definitely different b/w the 2 cars.
2. BMW says the steering wheels are not interchangeable per the ETK.
3. Vendors who claim that they are interchangeable can order the part for you but will not accept returns if it doesn't fit. So unless you have $500-$1,000 you are willing to blow on sheer curiosity. I'd pass.