Two cars one key?
 

Years ago with ford's double sided key you could cut one side for one car and cut the other side for a different ford car. Then you could use one key for two cars depending on which way you flipped the key. Has anyone that has two hhr's tried this? I know that you would have to program the key for both cars but it seems like it may work.

I doubt the key could be programmed for 2 cars.

There very well may be two sets of tumblers. I ran into that in 1974 when I bought a new Audi Fox. The dealor only had one key for it . They gave me a new blank only it was steel not brass so it had to be hand cut. The locksmith that did it said only one side had to be cut. He could not get it to work and I asked could it have two sets of tumblers, he said I know how to find out and quickly cut the bask side and it worked perfectly. The Porsche 928 has 4 sets of tumblers.

It may have more then one set of tumbler. I will have to do some checking on that.

BTW the key isn't programmed to recognize the car, it's the car that learns to recognize the key. If you have multiple GM cars with the same key blank, you CAN have the locks and ignitions keyed for whatever key you want, and then go through the programming scheme on each car so that all of the cars recognize that key.

You could have an entire fleet of HHR's on one key if you like.

I was thinking about that but then to do it right I would also have to do the drivers door key cyl. As well. I like the idea of one key for both cars but don't want to rekey mutable lock cyl. And I agree the car is programmed to accept the key so that part should work. I ordered a cheep transponder key on ebay when it gets here I will try it and see what happens. I will update when i find out.

Well I ordered a key from the internet and found a place that was able to cut the key with two different sides to it. Much to my disappointment it won't work. The key will work in the ignition of the 08 but not the door lock and will not work in the 07 car at all. :thumbsdow

Well, nothing ventured, nothing gained as the saying goes.

Sorry your idea didn't pan out, had it worked, it would have been super handy.