2009 (?) Nissan Rogue -- maybe a 2010, it was a recent model as it was a rental car.
Driver to passenger, all seatbelt installs -- RFing Scenera, Cosco HBB (harnessed,) Highback Graco Turbo:
Not tech-checked, it was a rental setup I used for about two days. If I recall correctly, the Turbo wasn't bad at all to buckle, due to the way the seats puzzled together.
2006 Honda Pilot, 2nd row, driver to passenger, all seatbelt installs:
RF MyRide, RF Radian, Cosco Ambassador/Evenflo Big Kid backless-- but pretty much any seat would fit here
Cosco Ambassador, RF Radian, RF MyRide
RF MR, RF Radian, RF Scenera
FF Scenera, FF Nautilus, Cosco Ambassador/Evenflo Big Kid backless
Evenflo Big Kid, FF Nautilus, Cosco Ambassador
Baseless SR22, RF Radian, RF MR
Plan on twisting the buckle stalks when they're long, except of course with the boosters.
I'm sure many other combos would fit, too. It's a pretty wide seat. Radian will only fit front-to-back RFing in center, although if you're not using the front passenger seat it would probably fit there as well. RFing seats will only fit behind the driver if you have this row all the way back, in which case you cannot fit RFing seats in the 3rd row. As long as you can puzzle on the driver/center position, I would imagine you could fit many (most) things on the passenger side. I will edit in other combos as I find them, since I don't have my seat setup finalized yet.
3rd row:
Several combos with a seatbelt kid in one position or another. My ~90lb, 53" (?) 8yo fits the belt back there, and his ~60lb, 48" 6yo brother almost does. Staying in position is, of course, another story.
After much, much work, I was able to get the following, driver to passenger, seatbelt installs:
RF Radian, RF Coccoro, RF MR
Many, many, many caveats...
1) This is a VERY difficult install. Although I'm not a tech, I have done many 3-acrosses, and this the hardest one I've ever done. It took literally hours, tons of combinations, and help from my roommate, to get it all in.
2) There are a number of installs that seem tight back there, until you check for independent tightness, and then they are VERY loose. This is especially true of the Coccoro, driver outboard. Beware.
3) I have not verified the MR install (nor have I used it yet,) but based on what I learned I'm reasonably sure it's tight. I just couldn't take out the other seats once I got them in. I'll need to use it this afternoon, so I'll be verifying/reinstalling at naptime.
4) Do NOT lock the shoulder belt on the Coccoro if you route it around the back, you will be very sorry if you do... it rotates the seat upwards and messes up the whole install.
5) You'll need to load these kids through the hatch.
6) The second row of seats will be folded down while you install these. Unless there's a way I don't know about, you have to put the row into its upright and locked position to get it to lock upright. Then lean over the seat, and move the benches all the way forward -- I think it's five clicks -- and that's the only way you'll have enough room for the RFing seats.
I also learned that the Coccoro and Nautilus do not fit in ANY 3-across combo. Nautilus does not fit at all on the 40% portion of the seat. Graco Turbo is nearly impossible on the 40% portion of the seat, due to the fact that the base more-or-less covers the buckle in such a way that it's extremely difficult to get it buckled. Cosco Ambassador actually works well.
This has not yet been tech-checked, once I get all of my seats (I'm still waiting for a booster or two to arrive) I plan on taking the whole vehicle to get it checked. I'm comfortable using the installs in the meantime; I tend to be pretty picky about my seats.
Editing to add:
I checked the 3rd row and determined the Coccoro was NOT independently tight in the center, though it was close. It was when I put it in, but I think I knocked it askew when installing the MR. MR was fine. It may have been possible to get the Coccoro okay, but in the midst of working on it, I discovered the MR actually fit in that same spot.
I took the process of install Radian, install MR, remove Radian. Check MR for tightness (it actually required me tightening it a tad more.) Put on MR locking clip. Uninstall MR. Install both Radian and Coccoro, checking for individual tightness. Reinstall MR.
Getting the MR to buckle is very, very hard. I've done it twice; first time I had my hand under the MR cupholder/between MR & CCO working the buckle while my roommate went through the hatch and practically did a jumping handstand in the MR. Second time, I went through the hatch, peeled back the MR cover and was able to get one hand thru the beltpath, and other hand between the MR & CCO to get two hands' pressure on the buckle, and perform a contortionist routine to sling one leg over the seat to get enough pressure in the seat to buckle the MR. It was pretty funny looking I'm sure, and scraped up my arm... I alarmed the dcparent in the driveway with my "GOT IT!!!" yell when the danged thing finally buckled.
After the whole thing is installed, I lock the MR belt, loosely. Or if I don't, the kids do, climbing in and out. If I have to take out the MR, I leave the locking clip on but unbuckle the belt at the plug (no clue what to call it -- the buckle that's not the normal buckle, lol,) so that it can retract enough to unlock without taking off the locking clip.
I have not taken a picture.