Door Hinge problems of the 2003 Volkswagen Jetta

My 2003 vw Jetta tdi GLS sedan was parked on a summer day (approx. 100 degrees f). Upon returning to the vehicle, I noticed a waxy, greasy, yellow substance leaking from below the doors on both sides of the vehicle. Upon further examination, I discovered that the substance was leaking from between the inside surface of the door and the rubber weather stripping. Contacted my vw service dealer (dana motors, billings, mt), and they informed me that this was a common problem with vws during hot months, that the substance was an undercoating protectant that was sprayed on at the factory. They also told me that it was not necessary to have this protectant replaced. The stuff has continued leaking out on very hot days, usually only 95+ degrees. It is hard to remove but doesn't seem to have done any damage to the paint. I want to know if it's true that this stuff doesn't need to be replaced. What if it's a necessary lubrication and by leaking out will harm a part of the door assembly?.

Consumer stated driver's side door panel had a release button that released the gas flap door. This button kept falling inside the door panel. Consumer believed this was very unsafe, could run out of gas.