Transmission sensor ( fail safe prog )

I have had to have my BMW X5 2004 transmission rebuilt TWICE in the last 2 years. First, @80K, it just stopped, though engine rev'd. When the trans place opened it up, they said the trans oil was burned, so they rebuilt it for $2,500. I had problems over the year and then it went again during the warranty and they repaired it, free. Lasted 14K Miles. I got ALOT of Trans Failsafe Prog lights. When I turned off the car, it reset, but ultimately came back on, and forewarned an impending trans failure. When the trans went the 2nd time, I bought a USED 40K trans from LKQ (I was lucky to find one with low mileage) for $2K and had the trans place put it in. NO PROBLEMS now. I got this advice from a BMW dealer parts guy out in PA - NO ONE can really rebuild BMW Trans well. Either go for a remanufactured one, or a low mileage used one. Getting them rebuilt at the local trans place will only give you heart aches and you'll end up doing the job again. ALSO: DO NOT WAIT FOR the BMW recommended 100K miles to replace the trans fluid. I suggest 60K. That's the #1 cause of trans failure. I'm out $6K on trannys now, but I'm about to take legal action. One more thing - I used K-Solv in my radiator, and the Trans guy told me that it clogged up the trans cooler. He took off the cooler lines and put a video tube camera up there, and yes, it showed cloggage. Jury is out on who's the real culprit here. Bottom line: Trans Program Failure is a pre-cursor to transmission failure. Get ready... Don't let a local shop rebuild it! Start shopping for a low mileage used one!