I took my '99 to an independent dealer last night with the idea that he could find me a newer lx with less miles, my car is very clean and has 90k, he said all he could give me was $18k and when I get 100k it will drop down to about $12k - does this sound right? It is a good thing I like my truck since I will be keeping it for awhile

No it is not. Your car will not depreciate by 6k (33%) by simply traveling 10k more miles. These cars have outstanding longetivity, why would you need to have a lower mileage one if yours already runs fine? My philosophy has always been that you always win by keeping your old car. You always lose when you trade in as the dealer must make a profit off of you one way or the other. It is cheaper to maintain a higher mileage car than to trade for a new one. For instance, buying a new car costs around $1500+ just in sales tax. That is more than the cost of a transmission replacement. Let's say you had to rebuild your engine at a cost of $3000. Assuming an average car payment of $500 your old car only has to last 6 months for that rebuilt engine to pay for itself. So if you still like your old car just keep it. Just my opinion.

Here's a little more good info for comparison's sake. I went to Kelley Blue Book and put in the 2 scenarios of mileage:

99 LX with 90k in good condition trade-in value: $18,915
99 LX with 100k in good condition trade-in: $17,990

That is a far cry from what Mr. Independent Dealer said huh?

Good grief, before you trade it in you might want to post your vehicle with pics here at Club Lexus. I have no problem picking up a quality 1999 LX for $18k. If you've got good service history you may have yourself a customer. What color is it?

whoa! that's very low, $12,000.00.... might as well keep it!