I'm not really sure if he's still there and/or still in business, but I think Jason Lockhart on Ringgold Road used to replace floor pans pretty resonable. He used to come to our club meetings, but I haven't seen or heard anything of him in about 3 years.
For major rust repair (frame rails, heater channels, etc.), you'll need to find a body man that is good with old hot rods. These guys are usually good at dealing with cutting out rusty pannels and welding in good metal. The only body shop I know of that specializes in old Volkswagens is Overton's Restorations in Tallapoosa, GA. It's a couple of hours south of Chattanooga, he's expensive, and has a long waiting list . . . but he knows how a bug is constructed, how to take it apart and put it back together as good (maybe better) than new.
For mechanical stuff, Jim Lockhart on Rossville Ave. or Harry Guin on old Ga. Hwy. 2 at the edge of Chickamauga Battlefield are about the only long-time VW mechanics still in business. I've never used either of these guys myself, so I won't give you a first-hand recomendation to use them. Maybe someone who has had some experice with them can tell you more. I've met both of them, and both seem to really know their stuff . . . maybe that's why neither of them work cheap.
For a convertible top, I've always heard that Grant's Auto Glass and Trim is the best in Chattanooga. I don't think I've ever seen one of their tops on a VW, but I have seen their work on other brands and it seemed to be top notch.
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