The Best: http://toy-lex.com/
Unfortunately, you cannot do this by yourself. You must go to a LEXUS dealer because these keys are laser precision cut. They only need to know your VIN and they will order the key to be cut from LEXUS. It may take about a week to get your key from LEXUS HQ.
The key has a button which controls the locks on the doors, press once for drivers door and other doors, if key does not work check battery in key.
hit the lock button twice
From SAAB., Your nearest dealer can get a key to match your barrel.
Dealer, locksmith............
go to the dealer
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.
If you press the unlock button two times it should unlock all the doors.
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
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.