I'll throw my $0.02 in as well - Any Radian car seat by Sunshine Kids; much narrow then your average car seat, so you can fit three abreast in an LR3 without any issues, or have any "free" seat fold forward without any difficulty - ie, for access to the rear, we'll strap one outboard and one center. The seats have steel and aluminum reinforcement instead of just plastic and as a result (at least in Canada) they can be used for 8 years instead of 6, and have weight limits of 80 lbs instead of the 65lb max for every other car seat I've seen (though many aren't that high!). I'd probably still start with a detacheable bucket, but the Radian's can be used from 5lbs upwards in rear facing mode - however, because the seat has a very high back, you'd likely want to rear-face in the center.
They also fold flat and can be worn like a very uncomfortable backpack (we travel with 'em several times a year) - the steel reinforcement makes them pretty heavy, but with backpack straps its fine for carrying around airports, etc, etc.
