I have a 2015 S60 with about 16,000 miles. Over ordinary city roads, the left speaker(with the blind spot signal) rattles. The dealer has replaced both left and right speakers and added a bit of stripping behind the left speaker. It still rattles. When I bring it to the the dealer for a drive, we can't find a road rough enough in that area to get the rattle going. (I am not talking about ROUGH roads, here.) So I drive home, get on the roads in the Twin Cities(Minnesota), and it rattles. The dealer is getting impatient and has no ideas. It rattles much worse in cold weather, so now that it is getting warmer, it rattles less. I think the dash area gets more flexible as the weather gets warmer.

Please help.

 

you sure its the speaker and not something else in the dash area? Seems they did the right thing by replacing the speaker and shimming to make sure its installed tight. About the only thing I can think of is find a dealer near some rough roads :-)