Only in America...
could people realistically discuss the idea of having a different automobile for each occasion: one for trips, one for around town, and maybe a really old beater for hauling the incontinent dog to the vet. God, is this a rich country, or what?
As a practical matter, I would bet a lot of families have to select a single car to cover all the bases. Logically, this would be the one that could handle the biggest jobs. I can take an SUV to the store, but I can't haul the family in a hybrid two-seater on a road trip.
This is probably why you often see Mrs. Smith alone in the big SUV or van at the grocery store. Wasteful, maybe, but probably not as wasteful as two cars her family would have to pay for.