Front Driver Side Air Bag Inflator problems of the 2000 Volkswagen GTI

I have owned the 2000 Gti since 10/2001. Purchased the car with 13,000 miles on it from the orginal owner. Currently the car has 80,000 miles. The car has only been serviced by the dealer it was purchased from campbell/nelson 24329 hwy 99, edmonds wa, 98026. In Nov. 2005 the air bag icon appeared on the dash. I took it in and after dealer diagnosis, a $101. 28 charge it was recommed driver's side-airbag with harness be replaced. Called vw America and they covered replacement. In oct. 2007 the light came on again. The same diagnosis was given but neither the dealer or vw America would cover. Since the car has never been in an accident and the airbags never activated the response of components wearing out makes no sense. I know of no other cases on airbag problems with other models. Either the dealer fix in 2005 or the component from vw has problem. The dealer will replace the system for $645. 02 seems unreasonable for a safety item.