Does anyone how to reset the maintenance light on a RX330 06.

If it is like the 09RX350, you make sure the odometer is set to 'normal' mileage, then turn off engine. Keep the button that changes odometer to trip mileage pressed, and turn key to 'ignition'. After a short while, a message scrolls across the odometer and the maintenance light goes out. You then let go of the button that changes odometer to trip. It is important to make sure you are in 'normal' odometer mode before you start the process, and that you turn the ignition key only after you hve the button pressed.
This si explained somewhere 'deep' in the manual.
Good luck!

Just for grins, I tried your procedure on my 99 RX300. Although I got no message in the ODO window, after holding the button down for about 15 seconds, i released the button and turned the key off. When i restarted the engine the check engine light was out. Wonder how long it'll stay out?

Amazing! (and interesting)!

Eight days later and the check engine light is still off

I guess it is an easy fx for all those 'check codes'. Who needs to change sensors, plugs, coils etc... anymore? (joke)

Well, after all, it's my wife's car.

Was it a maint req light or check engine light? Resetting the maint req light is much different than the check engine light. The maint req light tells you it is time to change the oil and get the scheduled maint for the mileage your car is at. The maint req light would not come on after 8 days unless you drove for about 5000 miles in that time period.
Jeff

Its the check engine light. Don't think I've ever seen a maint. req. light on this model and not even sure it has one. I'll check the owner's manual to see for sure but in the past, say for a 90,000 mile inspection, the check engine light comes on about 500 miles before the event and AFAIK there's nothing due right now. Like I say, its the wife's car.

The original query was about a RX330 or similar. The comment that came later concerned a RX300. The RX330 and subs. have maintenance lights. The (older) RX300 does not, but it seems the procedure to stop the maintenance light that works on the RX330 et subs. has the same effect on the Check Engine light of the RX300.....