Which convertible car seat is best for a small car or three-across?

The Graco SlimFit 3-in-1 is the seat most often recommended for tight back seats and three-across setups, with Consumer Reports praising its narrow design and csftl.org confirming its space-saving build. Note the disagreement, though: some r/CPST commenters argue it is still wide front-to-back and 'just as wide as Graco's other seats,' so measure your vehicle before buying.