We have three car seats across our backseat. We have a maxi rider (for DS) and two other cheaper car seats, one is a fisher price one I think, the other is a red and black sporty type one - can't remember the brand. They all fit easily across our backseat, BUT, we have a 7 seater Mazda MPV. Plus its awesome since its a van, easier to get the kids in and out of their seats cos I don't have to bend over putting them in, I just lift them into their seats.