Tank Assembly problems of the 2001 Acura MDX

I have a 2001 Acura Mdx that I purchased new. In July, I noticed small drips of oil under the vehicle. Upon getting it examined at a local mechanic, I discovered that the gas tank had developed a leak along its seam! I contacted the dealership(Acura of tempe) and they said this would not be covered under warranty. I also contacted my insurance company (ameriprise) and they said this would not be covered under comprehensive coverage and to them it appeared to be a manufacturing defect. Since the Acura dealership had quoted me a cost of repair that was more than 30% higher than my auto shop, I chose to go with the latter. I feel this defect is a manufacturing defect, and could have been a very serious hazard if left untreated. Acura should have paid for this repair. I would appreciate your suggestions / feedback: do you know of other complaints along the same lines? note: I have 2 pictures of the gas tank showing the leaks that I can send you if you like.