My friend's Jetta had its brake pad lights on ever since he did a trip out to the desert. Having taken it to both a mechanic (who wanted to replace the brake) and a brake service center (couldn't find anything wrong), the folks at Volkswagen found that it was just the brake pad sensor that came loose.
As for customer service, Chad at the service desk explained everything very thoroughly and he was adamant that if anything was found that needed to be fixed, he would call right away and ask for the go ahead before they do anything. Which he in fact did!