ard, thanks for the info and recommendation. I've read many of the links you posted but I like the idea of calling for a recommendation.

The indy I mentioned is in fact a transmission shop and not simply a BMW indy. They quoted me $2,200 to replace and reprogram the mechatronics module. He admits it's not a guaranteed fix. He also says that the next step would be to rebuild for an additional $1,800. This is essentially a $4,000 gamble as you point out. This would come with a 12 month, 12,000 mile warranty.

The other option is to replace the transmission with a remanufactured unit from BMW at the dealer at a quoted cost of $7,350. I'm pretty confident I could get this reduced by 15% which puts it at $6,250. A difference of $2,250 from the option above but likely guaranteed to resolve the problem. This would come with a 2 year unlimited mile warranty.

The car is a 2008 3.0si with 96,000 miles. The issue started around 87,000 miles and has gotten much more frequent but not worse per se. The most frustrating part is that I am a VERY conservative driver and can't imagine the issue is due to excessive wear and tear as 90% of my miles are highway. The dealer has done every scheduled and recommended service as well as oil at half intervals, ie. every 7,500 miles. The water pump and plugs were recently replaced at around 90,000 miles. I have not done any previous transmission maintenance.

Decisions, decisions!