The passenger side rear wheel had an improper casting from the factory. the rim had a failure at freeway speed with no damage, signs of impact, or puncture to tire. the tire remained on its bead while vehicle came to a full and complete stop. the rim failed by having a two inch hole blowout from the inside of the rim causing a sudden loss of pressure to the wheel. there was no contact with any road debris or hazards. the flaw was identified by an excess amount of wheel weight, used in the tire balancing process, within 2 inches of failure signifying a lack of material in that area of the rim.