I have a 1997 with 160,000 miles, I have all service records from mile 1.
While trans has been flushed every 30 to 40k, my lexus dealer service rep has suggested a B&G "Power" Flush and refill of the entire system. Fortunately, this person has treated me well over the years. He has encouraged my mix of DIY (oil, air, cabin filter changes, broken antenna fixes, etc) and dealer service (timing belts, etc). He has matched parts prices to those found online at Lexus of Pembroke Pines (a great source for OEM Lexus parts). In other words, no complaints.
I am having no transmission problems but have probably lost a litttle "smoothness" over the years. I would like to drive the car to 300,000 and maintain it accordingly. If anyone has an opinion or experience with this type of service for trans, brakes or otherwise, I would appreciate it. The information from this site has been invaluable, thank you.
P.S.: If you know of a good independent shop in the Metro Detroit area, I would love to know about it.