Buttons an camera also working without canbus-box.
You have no benefit from buying a canbus-box for Suzuki, as long DUDUAUTO doesn't implement it.
To get the camera to work you just need a 2 dollar cam adapter. And you can use the normal power harness.
I hope, that it will be possible to get all informations from OBD can. Becsuse you get ALL informations from the OBD socket. Even TPMS.