Nev

I thought the stereo +12v feed on
the 147 wasn't switched.

You can turn the stereo on without
the keys in the ignition.


So sounds like it's wired up as always
on at the moment.


The steering wheels button are not connected
to the stereo directly, they go through the CANBus
so you'd need something to interface between the
CANBus and your new stereo to get them working.