Which Lexus model would you recommend for me?

I drive a 2006 Lexus IS230 Exec; 195,000km. I want to trade it in for another Lexus, possibly three to five years old. How much could I expect to get on my car for trade in. When would be best time to trade - before or after Christmas? What model of car would you recommend? Current car has full service record with a Lexus garage. I would appreciate your advice as I am clueless about this type of transaction.

Aidan: Given the age and mileage of your car, I think you would fare better by selling it privately. Approaching a dealer with enough cash to buy a three to five-year-old premium saloon at a time when they are actively looking to run forecourts at a much leaner level would put you in a strong position. Don't expect to rob a car from them, but insist on good service, a nice price and a clean, well maintained car.
 Forget your own car for now. Talk to your Lexus dealer. Tell him you want a newer IS model on a straight-cash basis for now or after Christmas, which ever works best for them. Drive a good hard bargain. Hewill know your car is sound as it has been serviced there, so ask them to advertise it and sell 'as is' for whatever you can get - and say you will pay a good commission. That way you are getting a newer car at cash-only price and you don't have the hassle of trying to sell your old one.