Will KALLAX Shelf unit, white, 30 1/8x30 1/8 " fit in an Audi A4 Avant 2022?

The A4 Avant pairs a wide mouth with real height: the opening measures 40⅛″ across and 33½″ tall, so upright boxes pass through without a tilt. The floor gives you 41⅜″ with the rear seats up and 72″ once they fold, a gain of 30¾″, with 39″ between the wheel arches at the tightest point. The lift-over sits at 24¾″ and the floor is only 2″ below it, almost level, so long boxes slide in instead of dropping in. Tall furniture cartons and long flat packs both do well here; extra-wide boxes meet the 39″ pinch first. Slide heavy loads across the sill on a blanket rather than lifting them over.

The 2x2 KALLAX is one of the easiest IKEA packages you will carry: a single flat box of 31¾″ × 16¼″ × 7½″ at 37 lb 8 oz. At under 32″ long it fits in nearly any trunk without folding a seat, small hatchbacks included. The weight is the only catch: it is dense for its size and the cardboard gives you no handholds. Carry it upright against your body rather than flat by the ends, and lay it on its wide face in the trunk so it cannot flip over on the first speed bump.