PSA: getting three child seats in a narrow car

I can't find it, but there was someone with an E46(?) M3 asking about three across seating a couple weeks ago. I was in the same boat, but I've cracked the nut for the E36...

The Diono Radian R100 has a steel rather than plastic frame and is very, very narrow. They're a couple hundred bucks on Amazon. If you're having a kid and own smaller cars, just start out with one of these things. It's also a big step up in terms of material quality over even the nice Britax that came before it and can hold my 7 year old in 5-point harnesses for what looks like quite a bit longer. They go rear facing, but they're huge in that configuration, so you'll still need a seat that can stay rear facing until it's time for forward facing.

Specifically: three R100s fit in the forward facing position in the E36 sedan with room on the outboard sides to spare and no trouble getting them in place. Two forward facing R100s with a Keyfit 30 w/ base in the middle also works. The keyfit is good to 30lbs, so long enough to get them forward facing. Keyfit, forward facing R100 and a booster on passenger side also works, since the belt receiver sits outboard. The narrowness also means it's the first one I've owned that actually seats properly on a contoured bench. With the top tether anchors (dealer item) this is the first time I've had one feel properly stable. Loading/unloading will suck a bit, and it's not as safe as a modern car, but as a weekend/backup car, it's very doable.

In the wife's '05 Accord, there's LOTS of room with these setups that will hold us over until we find the right van.

May this information save someone else from swapping an M3 for a Mazda5.

Looks tighter than it actually feels in person. Seats are adjusted for a 5'10" driver and 5'8" passenger:

I can't say enough good about the Diono seat we have. I purchased a Diono Radian RXT to use in my 996 for my son who is two and a half. He has plenty of room behind the passenger seat, and my wife can sit in front of him comfortably. It is a very sturdy seat (heavy too - not fun to get in and out of the P-car).

The euro-designed seats, while expensive, are tailored more to smaller vehicles usually. Who needs a van?! :)

The weight is pretty spectacular. The car just gained about 100lbs with those two seats. :P

I've seem photos of these things tucked behind the driver in classic 911s. Which gives me all kinds of bad ideas...

How do you heft the baby into the middle?

I solved the problem with one of these:

My concern, no matter how good the child seat, is how close to the door are they sitting? If they're pushing up against the armrest, even the best car seat won't help much if you get t-boned. That's one of the biggest pros to a minivan...my kids are far from the doors.

Thank you, this is pertinent to my interest.