Will FRANKLIN Bar stool with backrest, foldable, counter height black/black, 24 3/4 " fit in an Alfa Romeo 159 2010?

The 159 gives you plenty of height at the opening and less width than you would like. The mouth measures 36⅝″ wide by 50¾″ tall, so tall boxes go in easily, and the floor matches it at 36⅝″ across its narrowest point. Length runs 40⅛″ with the seats up and 69⅝″ folded, a gain of 29½″. Wide, rigid cartons are the ones that fight you here. The sill is 30⅜″ off the ground with a 9⅞″ drop to the floor, so lift over the lip and lower, rather than sliding.

FRANKLIN is about as friendly as IKEA packaging gets: one flat box of 43½″ × 21½″ × 5″ at 12 lb 2 oz, because the stool folds flat before it ever meets the carton. A box this thin slides across almost any back seat, and most trunks swallow it without folding a single seat, so you rarely plan a route around it. The number to respect is the 43½″ length; a small sedan's opening can still argue with that, so check the trunk mouth if you drive something compact. Lay it flat under heavier boxes or stand it on edge against a seatback, and it rides home without complaint.