Would this fit in the back with 2 Diono Rx seats ?

Hi Alyssia, our recommendation would be to put the 2 Diono’s in and then measure the space left for the possibility of the Graco Turbo Booster. The Graco Turbo Booster is our most narrow booster at 41.9 cm and that is at the widest point. Allow an extra 1cm of space on the side of the Graco Booster so you still have space for the belt to go in. We would obviously recommend also going in to your nearest store once lockdown is over and then you can actually try the seat out and see how it fits in your vehicle. Thanks