After using the American Express Network’s Auto Purchasing Program, which is administered by www.zag.com, it didn’t take long to discover that the participating dealers which provide quotes with “Price Protection Certificates” for your configured vehicle have no intention of honoring those prices. They merely use the service as a source of sales leads. FYI, other buying services that go through Zag.com include USAA, Consumer Reports, Overstock, Bank of America, Sallie Mae, NEA, and others. Dealers not... read full review »