AMC had a subcompact turbocharged 4WD minivan concept in 1977: the AM-Van.

It was shown to the public as part of AMC’s “Concept 80" campaign in 1977. AMC had an all-new subcompact vehicle platform in the advanced design stages at the time, but later concluded that the company didn’t have the money to tool up a completely new design. 

Its small size and expected low price would have likely made it an unprofitable venture, anyway.

But the AM-Van, AMC’s 4WD turbocharged subcompact minivan, debuted to massive public interest when it was shown in 1977. I think it looks fabulous.