I'd say spread out in as many places as possible, too...
Yeah Facebook is great for things like car tuning, where the target age is pretty young and more likely to be on facebook, but if you're aiming to Jukebox enthusiasts, certain guitarist types, classic cars etc they are probably an older demographic and are more likely to be reading, say, classic car mag or even use ye olde yellow pages.
Also, have you looking into car / guitar / jukebox / whatever forums? See if you can buy a banner or similar?