The GM tranny, in different guises (GM model#4L40E & 5L40E BMW A5S 360R/390R),is available in the BMW 3 series 2.5 L/2.8L engines USA/Japan, BMW 5 series 3.0L Diesel engine (world wide), X5 series 3.0L engine and the Caddy CTS. I'm also told it is in the Jaguar but they re-engineered it with stronger internals.
I have the ATSG full service guide for complete troubleshooting/repair including an internal wiring diagram.

Thanks for advice and information.

I finally decided to eat it, and just get it fixed.

Performance BMW quoted me the lowest R&R at $6100... so there goes that money.

They also said I needed lower control arms, a new battery, window regulator, lock actuator, belts, and a new instrument panel display.

I was able to get the display through BMW NA at 75% off... and that's about the only good news.

I plan on just fixing the transmission and trying to do the rest of the work myself, short of the control arms. I think I'll just ride it with "less than BMW standard handling" for awhile.

Yall have a great week.

Sincerely,
Jim Kennedy
[email protected]
http://www.thekennedycompound.com

I do not mean to bring back a dead thread.. But if anyone else reading this post has this issue. If you have the GM transmission (5L40E)

YOUR TRANSMISSION IS NOT ABOUT TO DIE -- Your problem is likely within the valvebody

Check these out.
Common Causes of GM transmission (5L40E) No Reverse and Possible Solutions - Bimmerfest - BMW Forums
***Possible No-reverse solution for GM tranny owners*** - Page 12 - E46Fanatics

If you do the job yourself, you're likely looking at around:
$450.00 for a remanufactured valve body with sonnax kits
$100.00 for transmission fluid
$30.00 for a transmission filter (not needed but I recommend it while you're already in there)

Thanks for the info... fortunately I sold that Hex-5 back in 2009...

Unfortunately the Wife now just drives a 2009 Toyota Prius... haha.

I hope no one Has that problem!