Did we have car dealerships? Yes
Were the lots full of minivans and SUV’s?. No
Were minivans available in 1975? Sort of - Although the actual term ‘Minivan’ was not widely used until 1984.
Were they widely marketed, or have more than a minimalistic market share? No. Not before 1984.
You’ve got to love the internet - one off-handed comment on how we used to travel in much more cramped quarters is almost guaranteed to draw a know it all comment on the history of minivans. I assure you, I was not living in a parallel universe in 1974, where were the only people who did not own a minivan...most people had a car or a station wagon, a few suburbans were around, some had full sized vans....but no, everybody in the neighborhood most certainly did not own a Chevy Greenbriar (sic).
No, a lot of them owned a VW bus however.