I'm sure someone comes in periodically to check. Most car manufacturers realize how valuable feedback can be, and rather than reaching out to random consumers, they will generally browse various forums to get real world data, especially since most phone/mail surveys don't address specific issues or allow much elaboration. Browsing forums allows "common" problems to show up that might otherwise be overlooked through a survey because either it's not specifically addressed or perhaps the consumer feels it's not that big of a deal to mention.