GM used the all plastic boy panels on the Lumina sports van (minivan) and Olds and Pontiac versions. I had a first year (1990) Lumina and loved it. Excellent gas mileage in the mid 20s. If they had kept that sleek body, which was slightly smaller then other minivans, and dropped in a decent turbo four, it would be killer.
Of course the front sub frame eventually rusted out, but that was after 300,000 miles with no major repairs. Those 60 degree GM V6’s were very nice engines available in 2.8, 3.1 and 3.4 liter versions over the years. They were just old school, starting with carbs, then throttle body injection and ending up with multi-port injection.
The 4.3 liter, 90 degree V6 that shared tooling with the V8s was a rough running beast. although it did make good power.
Dennis