Mercedes-Benz has said that airbags for rear-seat passengers will soon be fitted to one of its luxury models - presumably the next S-Class, which is not too far on the horizon.

The 'Beltbag' as Mercedes calls it is basically an inflatable seatbelt and it's believed to lessen the risk of injury to rear-seat passengers during frontal collisions by reducing the strain on the ribcage that's usually caused by the seatbelt.

Once the airbag control unit detects a severe frontal impact, a gas generator inflates the multi-layered belt strap with Velcro seams to three times its normal width.

The belt is also comfortable to wear, according to Mercedes-Benz, which says its extra-soft belt strap edge allowed it to gained top points in practical trials for being “extremely comfortable to wear.”