Not really been doing a huge amount of mods to the X5 but I thought this was neat little thing that might interest some. I bought some 'T10' LED lights and they fit directly underneath the doors (I believe they're puddle lights?). The halogen ones feel a bit outdated to me so I thought I'd have a stab at changing them. Bit of a noob job but might help someone
Total cost £3.27 or about $5
These fittings can be found underneath all four doors, the boot/trunk and in the glovebox. To remove them just get a small flat head screwdriver and push it down, there should be recess for you to do this. Once it's out it should be dangling by a wire, just unplug it and take it off.
Then follow these steps. (Apologies for the crappy iPhone pics, my bad)