Does GM stand behind their products?

I recently found out that VW doesn't stand behind their products and I may be buying a 2004 Cavalier or 2005 Cobalt soon, if my car makes it that far.
The biggest selling point of the Cav's, besides the price and being able to get parts and service anywhere is that the Ecotec motor has a timing chain instead of a belt. Even though my Golf turbo-diesel averaged 51 MPG, when you factor in the belt change every 40K mi. and the $40 fuel filter every 20K, the Cav/Cobalt comes out ahead. (ignoring the fact that the VW is paid for already)

Your opinions on GM's credibility would be appreciated and also, for those who drive mostly highway miles, does the Ecotec 2.2 live up to the 37 MPG?

Thanks,

Steve