As standard, the rear seats in the 4 Series split and fold 60:40. Once folded down the backrests sit at a slight angle rather than fully flat, and the parcel shelf is fixed so there is a restriction on the height of objects you can fit into the boot.
However, you can spend a bit extra for seats that fold 40:20:40, with a useful ski hatch through the middle for longer items.
The front seats return to their original position, so the driver won’t need to reset them every time someone climbs into or out of the back. The seats themselves are easy enough to fold, but can get caught on the rear seatbelts.
The 4 Series comes with a belt-extender so you don’t need to reach back over your shoulder to buckle up when setting off. However, it’s odd that lumbar support for either front seat is not standard on any version.