If you need to fit 3 across the back you will need narrow seats. These seats are the narrowest booster seats we supply. Unfortunately in most cases you wont be able to get 3 across the back due to cars not really having 3 full sized seats. We try to give accurate measurements but remember that we can only give information we have from the manufacturers.
Also remember that the measurements for width differ for different styles of car seat, for example the widest part of an Infant car seat is where the handle joins the body of the car seat however a booster tends to be wider at the base.
The best thing to do is to visit an good independent shop for specialist advice. We are based in Berkhamsted, Hertfordshire.
If you have any specific questions please email us at firstname.lastname@example.org and we will do our best to help.