How to car seat back to RF?

I desperately want to turn my ds's car seat rf. He had it ff for about two~three months (but then we don't drive a whole lot here in nyc). He's now 15 mos. old, 26-ish lbs. The only problem is that we have a very small car. A two-door coupe. I tried putting the seat in the middle. But then my dd's little booster wouldn't fit on either side. And he's getting very heavy to maneuver behind the passenger seat.

What else can I try?

After reading the other thread on safety concerns, I'd like to reverse him. [just pray to God he doesn't start screaming or something...but it's worth a shot]

Just brainstorming for ideas. Any suggestion would be much appreciated.