When I bought my 97 SL1, it came with two keys. The ignition switch had been replaced and the idiots who did it did not bother to have the switch coded to the car.
Today, while doing some other work to the car which involved having one of the door skins off, I decided to pull both door lock cylinders, the trunk cylinder and the ignition and get them coded to the key to my 95 SW1. Now one key works both cars. Locksmith charged $40 to recode the cylinders.
-David