Fuel Delivery problems of the 2006 Saturn Relay

We own a 2006 Saturn Relay 3 that we purchased in June 2007. We have become aware of a design flaw that exists in Chevrolet uplanders and Saturn Relays that can lead to dangerous consequences. We have been advised by our dealership that gm is aware of the problem and has done nothing to rectify it. Because of the shape of the gas tank, if the car is idling while on an incline, gas dissipates from the engine and the car may stall. This can occur despite there being more than a quarter tank of gas in the car. Further, the car cannot be restarted unless set on a level surface. This has happened to us on two occasions. My worry is that it could happen in a dangerous place (I. E. In a traffic jam in a tunnel such as the Lincoln tunnel) where the car cannot be restarted and there is not easy access to evacuate. Gm is knowingly selling these models without disclosing the defect. Further, there is no disclosure after purchase until an event occurs and then there is no effort to remedy the defect.