An update on my transmission problem.
Lexus has agreed to replace the transmission for half the quoted $4700 cost.
Yes, the reason I bought the car to begin with is to avoid costly repairs like this, but I do have 108,000 miles on the car, so I was okay with the compromise.
I'll have to say Lexus was very pleasant to deal with. I even had to go through an out of town dealer for the negotiation. So I had no history with this dealer and other than the repair will have no future but still they were very helpful and accommodating. Lexus of Merrillville, Indiana was top notch, as was my hometown dealer in Louisville.
I also want to thank the people on this forum for all your input on this problem and suggestions for resolving it.