Main Motorcycle: 2010 Thunderbird 1600
Join Date: May 2011
Location: NC and FL, USA
Other Motorcycle: 2002 Suzuki Volusia
Mine (chrome) came with a replacement horn because it's a tight fit with the original one. The replacement is whimpy and tinny and (in my opinion) inferior to the OEM. If you slightly bend the original horn mount out of the way the radiator will fit without replacing the horn.
DrPat is right, snug up the bolt carefully. If it's loose the cover is prone to rattle and you'll have a new noise to deal with - a rattling, metalic sound when you go over bumps.
I'm a sucker for chrome - belt guard is next!
"Do what you can, with what you have, where you are." - Franklin Delano Roosevelt