It has become very clear that the '99 RX300 has some sort of serious transaxle design flaw that results in many (probably still a minority) of them failing "prematurely" in the range or 70-80,000 miles. Toyota/Lexus has made no admission of same other than oftentimes compensating, in some manner, owners of failed transaxles outside the warranty.
It appears to be indeterminant as to whether the '00 and later models of the RX300 series might or might not be subject to these failures. The fact that Toyota/Lexus adopted DBW with the RX330 probably addressed the failure issue since factory reps have said that DBW is used to "protect the drive train".
But I can tell you that the ATF in my 2001 AWD RX300 looked and smelled burned at only ~40,000 miles and I drained and refilled it. My 2001 had no requirement for ATF drain and refill but Bellevue Lexus insisted it needed to be done every 15,000 miles, EXTREME IMMHO. But the factory rep verified that yes, the 15,000 mile term was correct.
So here I am at ~65,000 miles, checking the ATF condition upon each oil change, awaiting the coming day (soon?) my transaxle will need to be replaced/repaired.
I ran a car fax on it, and it appears that it has about 25000 miles on it since repaired. is this a good sign? d