HB Booster for 2014 Highlander 3rd Row

[JobusMom]

I am trying to figure out how best to fit my 3 kiddos (6.5 yo, 3.5yo (still RF) and 3 month old) in a 2014 Toyota Highlander with second row captains chairs. Original plan was to move 6.5yo’s Britax Frontier to 3rd row but it is comically large and leaves no leg room.

Given that this is secondary car, I’m thinking it might make sense to begin booster training the 6.5yo in this car.

QUESTION: Does anyone have experience successfully installing a high back booster back there? Or, if no direct experience with this car, can you recommend boosters I should try?

The third row is somewhat tight and the seat strikes me as somewhat shallow (though I haven’t measured)

6.5yo is 47lbs and about 47” tall.

Thanks!

[2BunniesMommy]

My mother in law has a 2010 Highlander. I am not sure if there was a body style change between those years or not, but we have easily used a high back Graco Turbobooster in her 3rd row. Even if they are somewhat different, it is worth a try. No other ideas, because that and the no back literider are the only boosters we've used in her car.