If you bought a used 2004 Lexus RX330...could you take your keys to the dealership, and buy a key fob tht would work for your vehicle?

 

You should be able to, but make sure you have "proof of purchase". I would suggest taking the car in. You can also buy fobs on E-Prey, and then have dealer program. Not sure what the cost would be, so you may wna tot contact your closest Lexus Dealer and ask.