Big thanks to Rasmus for this. I bought a Move Up! without M+M just assuming you could add it easily later (as you can with a Citigo). I've successfully done the retrofit this week using Rasmus' instructions. It was stressful, but worth it.
I would urge others to think carefully before doing this. I think I ended up with a dashboard hole in the right place, of the right size and the right shape, more by luck than skill. It would be VERY easy to get this wrong by mis-measuring or just slipping whilst cutting. It would also be very easy to scratch the dash whilst messing about with the radio unit.
My biggest problem turned out to be that I kept getting the wires behind the radio jammed when I reinstalled it, so it wouldn't go all the way back in. It took many, many attempts to get them to move back through the hole behind the radio as I re-inserted it. Any tips on how to do this? Also, I'm still not clear where exactly the cabling is supposed to clip onto the dash structure.
I don't think Rasmus said how he actually cut the hole. I considered many options, but ended up using a Dremel. I drilled a series of small holes, very close together around the edge of my guide line (on masking tape, as Rasmus showed) and then joined the holes using a Dremel cutting bit. I then used a grinding bit to smooth things off. This did the job well.
Without this forum, and particularly Rasmus and those who helped him, I'd still be kicking myself for not specifying M+M when I ordered. Thanks again.
