facebook pages for general car audio are so full of dis/misinformation and derelicts, i get bent out of shape all the time trying to keep these retarded kids from burning their shit down or making absolutely retarded suggestions. it's the lazy-mans source of information that's not even remotely easily searchable when the work isnt put in by the page admins,... there are some exceptions within the niche topic and product pages, but for the most part it's a shit show with scammers lurking everywhere and the user's ability to delete their own posts. the audio snobs and know-it-alls tend to be more demeaning and full of themselves, as well.
i prefer forums as a paramount source of research and information, however, i had to start of few f/b pages of my own to keep up with the times, but i always try to supply links to forum pages.
