Question Booster recommendations for tight three across

My SIL has a 2003 Mazda 3 and is due with #3 this week. Her DS is 6yo, not sure on height or weight but is slightly over the top slots of his SK Raidan. DD1 (almost 4) is also riding in a SK Raidan and fits fine. DD2 will be riding in a SR32. What boosters should I recommend to her that will puzzle well with a Raidan and/or a SR32 base?

Current set up has both RN's outboard with the SR32 in the middle. I believe they would prefer it this way as both mom and dad are tall (6' plus).

She may be open to ditching the SR32 and using the other Radian RF as I know she is considering babywearing as a means of managing two kids and an infant in public. However, front-to-back space would be an issue with a RF Raidan at the infant angle.


Could a 6 YO (turned 6 in Feb) go straight to a backless? I think a Literider would fit. He seems to have good impulse control but he does have a disorder called Ocular Motor Apraxia that has caused delays in gross motor skills (crawling, walking, running). He is walking fine now but did not learn how until about 2 1/2. He can run but has his own way of doing it. It is almost like a "gallop" (imagine Neil Armstrong on the moon).

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Second question and may be worthy of a second thread...
I know the SR32 fits in the SR30 base but is it OK to use the SR30 base for the SR32? I thought it SR30 in SR32 base was OK but not the other way around but then I saw a graphic from Graco saying it was OK. Thoughts, caveats, if-then, or other qualifying statements?

TIA

The parkway fits well next the radian in both directions. It would be easier to buckle next to a rf radian.

I was able to use a Vivo with RF and FF Radians in a tight 3-across (Prius) recently.

There's only one replacement base at BRU now for 30/32/35, and it is basically the 30, so rather narrower than the 32/35 base. It fits fine, it's labeled for all seats, and it may be a nice narrow choice for three across (if it's not cheaper anywhere else, she can use a 20% coupon at BRU and bring it down from $48.99 sticker price).
I'd probably be fine with a non-car-napping 6 yo in a backless, I noticed my own dd's shoulderbelt started staying on her really well when she hit six, her shoulders were like too narrow before that age. Graco Connext is also a nice narrow choice, or cosco topside, but if LiteRider works, it's about the cheapest (Top Side requires the shoulderbelt to be above the armrest on the buckle side, the fit is *awesome* in some cars, and *strangling* in others, so buy-try-return that one from Target if necessary).

For a backless booster the one that has worked well in the tight 3 across in the 3rd row of my van is the Cosco Ambassador/HighRise (same seat, two different names.) It is narrower at the armrests so it makes it easier to buckle.
And oddly the Monterey worked 3 across in dh's small car for the same reason....it was narrower at the armrests but the Monterey may not play nice with the other seats. I had it puzzled with a FF MyRide.

I also just recalled that the Harmony Dreamtime Highback is narrow and might work.

There is always the RSTV (vest) too. Not my favorite for an everyday use - but it's not awful either.

Lite rider works beautifully in our Prius three across (FF Blvd/lite rider/FF Radian).