I heard Manos was coming to Nashville in August, but it is next to impossible to find a tour schedule on the Internet not five years out of date. So to make a long story short, it's sold out, not that you could ever know through Rifftrax.
It's in July or August or something. The Rifftrax facebook is the best place to get that kind of info. The website can be dodgy. Remember, though, you don't actually have to go the physical location...it's streamed to other theaters. I'm lucky enough that one of my local megaplexes actually has done the live Rifftrax events. Kevin Murphy said the reason they don't do them continuously anymore is because it's hard for them all to get together to do it on schedule and apparently the events don't really make much money for anyone involved, so it's hard to rent the theater space and all that jazz.