Mate, if it's still out will you take some pics please, esp the wiring. I'm replacing my mates stereo in his vivaro very soon: already bought the single DIN face adaptor but waiting for him to have some spare cash before buying a head-unit.

Can you not get an adaptor for the aerial: there's a plug one with a pin, but also a reverse adaptor to make it a female connection.

What's the "my unit has 2 holes in the back and the vivaro has plugs for 3!" bit ??
Do you mean the wiring loom? Is the 3rd not for steering controls?