My responses here are directly addressing the OP's situation (who has one 10 month old child).onourway wrote: ↑Fri Feb 14, 2020 3:27 pmI didn't misread anything. I was not making recommendations for the OP...
I can find plenty of evidence of people fitting 3 car seats across in a Model 3. I haven't yet seen evidence of 3 boosters across other than the inflatable Bubblebums which fit in just about anything but are not a permanent solution, IMO.
Discussing a hypothetical person with three kids at the same age/height/weight who needs to fit 3 BOOSTER seats at the same time is irrelevant to this thread and the OP.
Nonetheless, it still seems possible to fit 3 boosters if needed.
I'm not sure why you feel the Bubblebum is not a "permanent" solution...
The BubbleBum meets and exceeds the safety requirements of the FMVSS213 (Federal Motor Safety Standard for USA).
The BubbleBum is made from a durable material, similar to that of life vests. The integrity of the structure of the seat comprises of memory foam and a strong webbing harness.