Hello...little advice needed

[Learjetcap]

Hello all, great site. Funny story, my 1997 E36 M3 that I picked up 11 years as a CPO popped out of gear at a gas station, rolled 50 yards and T-boned a massive RV while I was inside paying. When I got back, it rolled so far I thought it got stolen. Insurance is talking about totaling it. I absolutely love the car, my commute is 25 miles of very twisty back roads, and the thing has been dirt cheap and paid for since Clinton was in office.
Anyone ever gone from an M3 to an X5?
After much searching and reading, how prevalent is the transmission failure issue with these cars as they clock high miles? (my car had 190,000 with nothing major but a clutch at 10,000 miles ago)