My local dealer has told me that once a smart key, for an 2005, is programed it cannot be changed. Does anyone know if this is true? I have the chance to buy a pair from a totaled Prius.

Did you get an answer yet? My guess would be that the car gets programmed to the key, not vice versa. That would mean that the transponder on the key is factory set; when you get a new key, someone needs to input its code into the car's computer.

That's how it works for other cars. Don't know if the Priuis works like that.

maybe check http://priuschat.com/ I can't believe they can't be changed but have never tried.