Well, right now we have 3 across in our station wagon, but are planning on eventually getting a minivan.
First idea: get captains' chairs in front, like the Honda Odessey and remove one. Put two forward facing seats in the back and the rear facing seat in the front. Easy in and out for everyone. The only problem is with a captains seat the baby isn't going to see much.
Dh's idea: put the baby in the back and the twins in the captain's seats. Apparently he doesn't remember the rental van we had where the infant seat was rear-facing in the rear row. Not only was she bored and weepy, but it was a *huge* PITA to get her into the seat and then buckled in. We both bumped her on the ceiling of the van a couple of times and I nearly strangled myself with the seatbelt from the middle row a couple of times. Not to mention that I tripped on it nearly every time I put her in or out of her seat.
Good luck, taking the seats with you is a good idea. But also try fitting three across (if you haven't already). We didn't think it would work, but when one is rear-facing it usually sits higher and is out of the way of the forward-facing seats. I've seen smaller cars with three in back (like a Chevy Cavalier) and both my and dh's car easily fit three (Volvo and Passat).