[SPKFOX]

It's been a week, to say the least.
Every day something new I feel like I'm losing my mind. Cars for 195k miles on it, been stage 2 for most of it, with relatively no issues. Just general maintenance.

First off, my abs/dct/yellow(start off assistance! Driving stability! Etc) hand brake lights have been on for a while, they cause a small abs activation when I'm turning at slow speeds, but I haven't had time to take it to the shop and it was great otherwise still, figured a dirty speed sensor was the culprit. But that's easy enough to solve... Obd2 scan doesn't bring up a single related code, no steering angle sensor, no abs sensor issues, not a single one. So I let it be.

Fast forward to last week, all of a sudden a raccoon appears... Gets absolutely demolished, rips off the under belly splash guard, I tie up the transmission belly pan out of the way (it's not hitting any electronics), and a few days later I get the passenger restraint fault error, then it goes away. Then it comes back for good, accompanied by the red air bag light & seatbelt light. So I buy a set of sport seats to replace mine, haven't put them in yet because it's been getting weirder...

While driving around last weekend I get a "DRIVE CONTROL SYSTEM!" fault, now the handbrake light is red... Great. Nothing seems to be different, however. And then as I'm leaving Seattle I notice my gps is stuck in one position, and as I drive back towards that position it glitches along with me, spinning in circles as I go. At this point, my car will also no longer calculate average mpg or speed, they've gone blank...

So that leads to today, I tried to clean the alternator terminals thinking they may have gotten wet or dirty. Checked the battery tray and noticed there's water pooled at the bottom... Dried it out, cleaned the terminals (battery was replaced a year ago and recoded to match). I was monitoring vitals on the carly app, all voltage seems to be okay, except for when starting the car it goes from 12.6v, down to 10.9v and then goes back up to 14v after all the lights come on on the dash. I pulled codes again today and got,

-P0103 (maf, it's from my cold air intake it goes away)
-P0658
-U0100
-U0001

My tuner (DUDMD) thinks that alternator is likely the culprit, or some sort of connection. I was getting ready to do a big 200k service anyway like I did at 100k miles. Brakes, fluids, trans service, fuel filter, new filters throughout. I guess I'll add in an alternator, abs sensors and steering angle sensor to the list...

Any advice from experienced folks would greatly be appreciated, I'm by no means new to cars or working on/building them. But I am new to new model bmws and their quirks.

Appreciate it,
Spk.