Identically Keyed Cars

Is it possible to own multiple cars that use the same set of keys and alarm codes?

It occurred to me the other day while juggling keys for both our cars that it would be way easier if we had one set of keys that worked with both cars, though we’ve got a Honda and a Kia so I think that’s probably technically impossible. I wonder if there’s a third-party company out there that will re-key cars from different manufacturers to be identical?

I guess this is a good reason to buy a couple of Teslas, because if anyone is going to offer this it’s going to be Tesla.