I was wondering if it is possible to reprogram a non toyota smart key to work with the prius. If so how
You could install a parallel key system. Use whatever card key system you want, and install it like they do aftermarket alarms. A big project, but not impossible.
These systems often need one of the real Prius fobs to work, so you end up needing a fob to save a fob. As stated before, it's possible, but not practical. Tom