My Altis' key broke...I couldn't get a replacement cover, I even went to my Toyota dealer, he said we can't get you the cover/casing, and the only solution is that we replace all the ignition switch, door locks, switches and receiver- and give you a new set of keys. Cost 19k + 2k installation and 24 hours at the dealership. I said no.
Eventually, I found an alarm system in G9 for 4k, it had two keys with embedded buttons just like Toyota's original keys: 1 in light brown and the other in dark brown. It had three buttons on its face though, un/lock and mute.
I got that system installed in January, til now no issue and the key is intact. However, Im not using the "plastic" key that came with the kit, rather I replaced it with the original key...