The first thing is to consider how big the bike is and how much effort you're prepared to put into prepping the bike for transport. A compact road bike with no mudguards* will fit in a small hatchback if you take both wheels off, dropping at most one rear seat. QR wheels or through axles are a big help. You could do that almost daily. My tourer with security skewers and full mudguards takes a few minutes to fit in a large estate; even with all the back seats down you have to take a wheel off and fiddle.
You also need to consider what/who else you will fit in the car at the same time, as this affects what you might do with the back seats.
The vertical dimension is important: if the car is tall and the bike isn't (quite plausible as you're thinking of a minivan) it can go in essentially upright and facing forwards. Knowing the height from the ground to the bars/saddle and taking a tape measure to the car dealer can get you a long way here. Look for a flat floor at the tailgate rather than a lip, and the ability to fold down a single rear seat. Also note the bar width.
Aiming to fit it in the cargo space, consider the "bounding box" of the bike with and without front wheel: the length, height and width. This and a tape measure will allow you to eliminate many cars though a proper test may be required when you're down to one or two candidate vehicles, as you may be able to trade off length vs. width, especially with the front wheel off, and you may need to jiggle the bars to get in through the opening.
As bikes are an awkward shape for loading into vehicles, I suggest that if at all possible you do a real test when you're almost ready to commit.
* Or clip-on mudguards that work well.