I can easily fit two upright inside my Suburban with the back seat (but not third seat) in place, with fork clamps bolted to a 2X6. I could maybe carry three inside, but the handlebars make it tight, and more inconvenient. I can carry two more on a hitch rack (the type that olds the bike by the wheels, not dangling from the top tube). I can carry a 5th on my roof rack, and could carry two more up there if I bought the hardware.

I can fit one inside my Subarus, back seat folded down, don't need to remove the wheel, so only one inside compared to 2-3 for the Suburban. They also have the same external capability as above - same hitch rack (with receiver adapter) and same roof rack. So that car can only carry 4 (or 6), not 5 (or8).

Just buy the car you want and get the right rack(s). If you want to carry them both inside the car, with little muss/fuss, you'll need a fairly big SUV or one that you can remove the back seat.