We've sold the TT and have a 5th now but:
In storage, I put the bars just inside the door on a mat to keep them off the floor. In a CG, I discovered they will rest across the rear portion of the A-frame, one end on the frame and the other resting on the spare tire (mounted under the A-frame). I put one on each side so they're easy to get to when hitching up. They're kinda out of the way and not too noticeable, never worried about them walking off.
2013 F-350 CC SB 2WD 6.7PS
2013 Eagle Premier 351 RLTS
-SOLD- 2012 X23B
-SOLD- 2003 Ford Expedition 5.4, Bilstein shocks