Do you have a car seat yet? Not one of the infant ones, but a rear facing seat that your kid might be in from ages 18mo-3 or 4yrs? They're bigger than you think. I highly recommend to anybody expecting a kid to buy a seat now, and check to see if it fits in the car with the other seats in their normal positions (My SO and I are both tall. With a rear facing seat installed in some vehicles, one of us had to move our seat forward too much to be comfortable. This may not be an issue for others). With the seat installed (assuming everybody fits comfortably) see how easy or difficult it is to load/unload a 20lb sack of potatoes or a large watermelon into the seat. That's what you'll be dealing with for the next few years. That might make your decision about which vehicle to keep for you.
If you're shopping for something new, I'd take the seat with you too. The seller (or dealer) might look at you a little crazy at first, but you'll be spending thousands of dollars on this vehicle with the primary reason being child hauling. No reason to buy something that's going to be a pain to use.