One problem related to differential unit has been reported for the 1999 Lexus RX300. The most recently reported issues are listed below.
On or about 12/5/09 my daughter was driving home from work on 55 when all of a sudden she said the car seemed to lose traction and she said before she knew it she was inches away from going into a ditch and just missed hitting another car,thank god the traffic behind her did not crash into her. A guy she missed hitting got out of his car and asked if she was ok and that she almost hit him. We contacted Lexus that morning and was told to bring the car in so we had it towed and was given a loaner for about a week and was finally told what was wrong,the front differential was locking up &fluid inside was completely black from metal shavings to the tune of $5000. 00 we at that time asked if there was any recalls on the car because everybody we talked to said the car should not have done that,was told by the service guy there were no recalls,we went looking on the internet about differentials and happened upon Lexus website and there we found recall on my car 1999 Rx300 recall #72421 describing exactly what happened to us. Contacted Lexus was told it was not my car,not my VIN #,different manufacturer. After numerous calls to try and resolve this getting the runaround was told by the service manager he would be willing to do the labor for free and but did not feel like he should assume all responsibility and to call corporate was told by them that there was no recall that it was a "technical bulletin". And finally they would allow 25% off of parts and that was a final offer,also I received a $500. 00 gift card toward parts,there is a recall # . I took very good care of my car,spent $2000. 00 in 11/08 for work on the car. Besides the fact no one was hurt Lexus is giving me the runaround they flatly said no recalls even though their website has recall with recall #. I think they are taking advantage because we are women and supposedly was not going to pursue this. If the service guy said to contact corporate which we did as well as the bbb,and mr. Fix it from the sometimes.