Thanks for the link to the video, Peter. The Vixen was a nicely made vehicle, and they're a treat to see on the road because they have a very different proportion - very low profile.
I had thought that the ones with the raised, "custom van" type roof had been retrofitted, but the video shows some views of both roof types.
Also, I thought they were all BMW turbodiesels, but the video shows them fitting a Buick 3800/HydraMatic drivetrain. That was probably because the BMW ones were (I think!) all equipped with a manual transmission.
Thanks everyone for the info on one of my favorite vehicles of all time. It's right up there with the Corvair-based UltraVan, and the GMC motorhome of the '70's.
One other detail I remembered while looking at the pictures - the tail lights
were from the Pontiac T1000 (rebadged Chevy Chevette).