Originally Posted by X5Flyboy

welcome! I hope you have fun with your X5!

2 things..., as a 2001 x5 owner, I can tell you trying to upgrade the electronics is going to be your biggest "A-A-A-R-R-G-H!!!!" factor, as the plugs are round pin while all "new" electronics are flat pin. Next, when your water pump is replaced, be sure to install the aftermarket Stewart water pump, as the OEM pumps have plastic impeller blades. Go with the stainless steel Stewart and never have to change it again. The OEMs tend to last 60-80,000 miles (some more, some LESS), so it's best to figure changing it as part of preventative maintenance vs waiting for it to break (some have lost the engine also)

look forward to reading about your mods. take pics!