A friend of mine is looking to buy a spare remote for her RX300 because she has only a valet key and main remote key to her car.

Does anyone know if the remotes on eBay work 100% in terms of compatibility with the RX300?

Are these remotes also interchangeable between different Lexus models?

Is there any difference in terms of remotes between the RX300s made in different years?

What would be a reasonable price to pay for such a remote unit?

Thanks in advance!

Jon