Social media communities are often minefields for companies and their brands. Empowered consumers are sharing their unfiltered thoughts about product usefulness and customer service, and companies are grappling with how to engage and respond. Much of this commentrary is negative, so it was surprising to learn that one business segment, luxury auto brands, enjoys a disproportionately positive relationship within the confines of Facebook, Twitter, YouTube and the like.

A study released today by MH Group Communications and Forum Strategies found that more than 90% of the discussion and commentary about the nine major luxury brands (Acura, Audi, BMW, Cadillac, Infiniti, Lexus, Lincoln, Mercedes and Porsche) was positive. Online consumers, it seems, really like their fancy cars and really like to share their enthusiasm with others.

The social media engagement takes place largely in Facebook and YouTube, the primary social media tools these brands are using, and this sector enjoys a “privileged admiration” among a growing, but still modest, follower and friend base.

While some of the brands studied are largely absent or only modestly engaged with social media, there seems to be little risk right now of attracting naysayers when these brands do launch programs. Consumers, it seems, feel they are part of an exclusive club by owning or aspiring to own one of these vehicles, and as a result attach great value to being associated with one of the brands.

This, at first glance, is encouraging news for the makers and manufacturers of these cars and SUVs. But looking down the road they might just find that they, too, are driving through the social media minefield so many other industries (telcoms, airlines, computer makers and pharma) have encountered.

The problem is that these brands have not yet wrapped their arms around how to engage with and organize these communities, which are growing independently of the automakers’ marketing efforts. For example, the unofficial Facebook communities of the Japanese luxury brands almost always have more participation than official pages. Car dealers and owners often post as many videos to YouTube as the brands themselves. None of the brands has launched a serious effort to join the mushrooming conversation on Twitter. And none has an integrated, strategic approach to social media that ties their e-commerce efforts to their social communities.

Their lack of holistic engagement will ultimately become problematic, as growing social media communities become more democratic and the “unwashed masses” of car lovers crash the party and dilute the exclusivity that makes luxury brands so valuable.

Given the current positive atmosphere surrounding these brands combined with the potential for them to lose control of their positioning as online communities grow, now seems like the ideal time for them to get busy and craft more comprehensive social media approaches. Social media programs can no longer be considered a nice add-on to traditional marketing efforts, but rather should be viewed as a foundational element that drives interaction with luxury auto brand consumers.