Self-conforming rearseat air bag

An apparatus for helping to protect an occupant of a vehicle having a seat for receiving the vehicle occupant, the apparatus comprising:

• an inflatable vehicle occupant protection device inflatable from a stored condition in the vehicle adjacent a reaction surface to a deployed condition between the reaction surface and the vehicle occupant, the protection device comprising:
• a front portion presented toward the seat having an inflatable volume for receiving a penetrating occupant when the protection device is in the deployed condition, the front portion having a substantially constant thickness in the fore-aft direction from the top portion to a lowermost edge of the front portion;
• and
• a rear portion connected to the front portion and having an inflatable volume spaced from the front portion by a space, the front portion being positioned between the vehicle occupant and the rear portion when the protection device is in the deployed condition;
• the inflated front portion being movable in a fore-aft direction relative to the rear portion to engage the vehicle occupant regardless of the distance between the reaction surface and the vehicle occupant.