Car seat for USA travel?

[OneKindDuck]

Hi,

We are travelling to Florida next month for family holiday with 4 year old (almost 5) and hiring a car so will need a car seat, not keen on using one from car hire company as no idea what type of seat they will provide or what state it will be in. Was hoping to buy a seat to take with me but only recently learned that our seats are not legal to use in USA as must be FMVSS 213 approved as opposed to R44/R129. Struggling to find anything I can buy here that will be legal to use over there. Has anyone done this before/ can anyone recommend a seat?
She is 20.5kg and currently in a Britax Römer KIDFIX PRO i-Size High Back Booster in our car at home.

Appreciate any advice, thanks :)

I've never travelled to USA but I was in a lot of Disney world groups as very interested in it lol. I think other people have purchased one when in the states and then donated it(not sure where maybe the car hire place?). Can't recommend anything though sorry!

It's not possible to buy seats conforming to FMVSS 213 here because they are only sold in North America.

As your child is high back booster age, you could simply buy a booster seat here and take it as it's highly unlikely anybody is going to check which regulation it is approved to. Although it's technically illegal there is actually not very much difference between the regulations at high back booster stage, and there is an argument that it's safer to use a seat that you understand and know the regulations for rather than something completely unfamiliar.

The other option as said is to buy one when over there. I have heard of people having them delivered to an amazon locker at the airport rather than having to go and pick it up from Target or whatever.

We took an extra bag to carry child seats that we and the kids were used to.