Yea i've been looking for used inner lights but haven't found any yet, it isn't very noticible in person but i definitely want them.

As far as wiring problems, for pre 10/2002 X5's they are plug and play, I just twisted in the bulb sockets form my old lights and plugged in the wiring harness on the light. The problem that I ran into (which Andaya helped me with) is that the sockets from my PRE-facelift Tail lights do not (as easily) fit as snug in the facelift Tail lights. You have to play with them until you get a secure connection otherwise they will jiggle free just enough so that you get the error message on the dash. The light also may appear dimmer or off altogether. Once you get the secure connection you're golden, I haven't had to touch them since ~1 month so far. I could try to make a write-up if others are having problems.