Pretty sure you don't need an ISO converter if you just connect RED & YELLOW together. You'll need to manually switch the radio on/off but otherwise should be OK.
Don't mess with the CAN bus though as that can never be used on after market stuff
Looked into this now, not ideal, don't want to have to think about switching off the stereo when I switch off the ignition. So I guess my only option is to run a feed from the switched live! Hate using scotch locks, worst damn things every. I picked so many of them out the loom of my mini when I bought it.