I've not needed to do much with the car recently other than drive it, which I don't do all that much now anyway because I normally bus to work and back. Having said that I've had to spend some time on it recently, including today.
A few weeks back I had a problem with the right front indicator, after faffing around for a while, which included removing the airbox and then the front bumper, it turned out to be the bulb holder so I sanded the contacts and bent them out a bit, did the trick but it's an unnecessarily complex task.
Then, just the other day, my right front Xenon died, literally straight after the new WoF sticker went on (whew)! Long story short - the ballast flooded whilst it was waiting in the yard for it to be collected... how? Shitty BMW engineering. 😠
If this hasn't already happened to your E8x then read on because it will happen eventually...
I confirmed the HID light itself wasn't faulty by swapping it to the other side (terrible design, requires removing the entire airbox). I knew from prior research that the ballasts can flood, unfortunately this is a headlight removal exercise which requires removing the bumper (again, terrible design). With the bumper removed I pulled out the RHS headlight and it was sloshing with water... which had all drained to the housing that contains the (high voltage) HID ballast (terrible, terrible, dangerous design)...
I mean seriously BMW, do you not saturation test your vehicles? (No, they don't). The entire ballast was submerged.
Pulled the ballast, filled it with a ton of RP7 and left it to dry whilst I removed the other headlight to check that. The LHS was dry as a bone which aligns with many internet anecdotes, it's typically a RHS problem.
The permanent fix is simple, some 10mm drainage holes, I did both sides, as BMW should have done from the factory...
Tested, reinstalled, and ~4 hours later fixed. What a faff caused by a bunch of poor design decisions.
As I say above, if it hasn't happened it will if your car sees much water, including washing. I was lucky, my ballast was salvageable but many report they're not so fortunate so be warned.
Edit: my car is very rarely parked in the rain, garaged at home, inside carpark if I drive to work, it normally only gets driven on the weekends. Auckland's summer of rain hasn't helped of course and the day it was at the mechanics was Tuesday just gone, so a little bit wet!