03 4.6is electrical nightmare!! ABS/DSC, Self Leveling Susp - Help!

[E34Play]

A little rant before the current issue... This truck just continues to give me issues... I've put 16k miles on it in my 2.5 years of ownership... during that time, the following:

Battery went dead
Coolant Hose burst
Alternator died
Coil pack
Sunroof started leaking
DS exterior door handle broke
Window regulator went out
Transmission failed (3rd gear drum)
Alternator died again (#2!)
Coolant overflow sprung a leak
Timing chain tensioner
Coil pack again
Likely more I'm forgetting...

And now the present. I haven't been driving the X too much as the transmission has still yet to be replaced (It's fine to drive if you back off the throttle as it shifts into 3rd), but just before Thanksgiving she started acting up again.

First, and I don't know if this is related but for quite a while now there has been an issue with the headlights... they'll turn on just fine, and will stay on with no issues - until I start driving. Once in motion, anywhere between 2-5 times the headlights will turn off and then back on again, usually the passenger side first, sometimes followed by the driver's side. ONLY once I start driving.

A week and a half ago I went to take the car for a drive, and I got a "Self leveling susp inact" warning on the dash. Also noticed the heated seats weren't turning on.. or occasionally they would, but would turn off right away. Drove it a little bit, stopped for food, got in again and the nav screen displayed the "Code" screen which it has never done. It even set off the alarm when I started it... I got past that and brought the car home and parked it until this morning. I checked the battery - it was new from last year, but I installed a spare oem BMW battery I had (green eye) just to test. Car started up, but still had the code screen, heated seat issue, suspension warning, and now the ABS, DSC, and brake warning lights... I shut her down out of frustration.

I'm quite literally near the point of setting the damned thing on fire. I ordered a voltage regulator for the alternator to play with once it arrives - but what do you guys think could be causing this? I'm sincerely hoping this is all tied to one faulty component...