Thanks for the suggestions. Unfortunately, test riding the bike before taking it home from the LBS is not an option for us. I can't go to pick it up and the LBS is under-staffed these days and not likely to be able to let someone take my stoker for a test ride and she can't ride it on her own. We're still getting the fog horn sound and vibration through the saddles. S-o-o-o, I'll work on
LV2TNDM's suggestions this weekend. It's been to the LBS 3 times just to work on the rear brake. It's one of the biggest LBS's in town. I have to believe they would have fixed it if they could figure out how.