If you have your old key you can call a local auto lock smith and they will be able to use that key to make another one. If you don't have that key then you need the key number for your car to cut that key for your car. Last option go back to the dealer and they will cut the key for you, it is costly though. Good Luck
Lexus has to hook their computer to it to program the key to both lock/unlock and to start the vehicle.
The Best: http://toy-lex.com/
Lexus proprietary information. i could tell you but then i'd have to hunt you down and kill you.
3 button fob 2003 onwards cr1616
10% off Chrysler Car Keys30% 2nd Ignition Key
Car alarm in Lexus ES300 started going off at random when car was parked, not running. I changed the key fob battery (flat watch battery) with a new battery and it fixed the problem.
From SAAB., Your nearest dealer can get a key to match your barrel.
Dealer, locksmith............
go to the dealer
contact an authorized Mercedes Benz dealer
Try replacing the battery first. If the transponder still doesn't work, start searching the 'Net for a replacement key.
Go to the Mazda dealer and provide them with the VIN number and they should be able to get a key for you.