Is this small enough to be able to fit 3 car seats across the backseat?

Hi Ruby, thank you for your inquiry, we would need to know the model of your car to be able to determine if this would be suitable for you and what other seats you will be using to fit three across, you can contact your local store and they will be happy to do a fitting for you to see if this works. We hope this helps. if you follow the link https://www.babyonthemove.co.nz/store-locations/ this will take you to our online store finder. Here you can find contact details for your nearest Baby On The Move Store where one of our team experts will be happy to assist you in your product search and help answer any further questions you may have.