Ford Falcon 2009: Rust bleed

Within two months of buying my new 2009 FG Falcon XR6 I noticed stains coming from between the plate joins in the engine bay. The two different body repair shops I consulted told me that the staining was in fact "rust bleed". Both then informed me that this was a common problem in the FG Falcon, particularly in the engine bay plate joins, around the rear boot brackets and the panel seams underneath the chassis, where on further inspection more corrosion was discovered. I contacted Ford who arranged an inspection and repairs by the dealer, but Ford rejected the original dealer's paint claim and went for the less costly repair option of not fully striping back the entire engine bay. The dealer, on Ford's instruction then just partly rust- proofed the engine bay, but the quality of the work was poor and resulted in further damage in the form of scratches to the engine bay when reconnecting some of the components. I have since noticed further corrosion in the seams underneath the bonnet. It is now apparent that Ford is just doing enough to get the car through the 5-year warranty period by 'masking' the problem, which I'm very concerned will leave me with very expensive rust repairs in the future. My attempt to get Ford to guarantee their corrosion repairs beyond the 5-year warranty failed. What avenues are available to me to get Ford to address the problem correctly so that I'm not left with a new car that has a very limited life span due to major corrosion problems?