Yeah, we've been really happy with our Golf, too.
I went and checked out some back-seat views of the Jetta and Rabbit. My thoughts, based purely on looking at the pics...
The Jetta seat bottoms are pretty flat, which is good, but the seatbacks have some contouring on the outboard sides that could steal some room. The center seating position looks like it could be tricky because of the buried buckle stalks - you're probably going to
have to put a carseat there that will fit between them.
The Rabbit looks almost identical, except the buckle stalks aren't as recessed, which means you
might have a better chance of shoving a carseat between them.
What are the ages & sizes of the kids, and are any rear-facing?