Shaker 500 Speaker Rattle

Hey guys, I recently took my car to the dealer to get a speaker rattle checked out. They basically sound like they are blown... rattling at certain tones of bass and voice over the radio. Almost any male voice on the radio will send the buzzing and it is ANNOYING

The thing is, I never blast the system, I never top it out. How could they be blown? Will anything else cause a speaker to rattle in such an irritating and repetitive fashion? Has anybody else had this problem?

When I brought it in they claimed they couldn't reproduce the noise (of course, this is S.O.P. for squeeks and rattles: "we couldn't hear it"). So I came in and demonstrated it for them by simply putting on something with a little bass. They have ordered the speakers and will be replacing them.

2 questions:

Will my speakers do the exact same thing again? I will be using the radio in the same exact fashion: why wouldn't they fail again?

Will this be covered under warranty? I didn't ask the guy at the time because I was focused on trying to reproduce the noise, and they haven't done any work yet so technically I can still back out if they're gonna try to charge me to fix a FAULTY Ford product. What do you guys think?

Thanks a lot, I'm gonna post it here in case anybody else has the same problem:



Tsb 07-17-06 Buzz/rattle
FORD:
2005-2008 Mustang

ISSUE:

Some 2005-2008 Mustang vehicles built before 8/2/2007 may experience a buzz/rattle from the door panels when using the radio/CD player at elevated volumes or bass levels or voice broadcasts. This may be due to the window switch bezel vibrating against the door trim panel. This can often be incorrectly diagnosed as an audio speaker buzz or a bad speaker.
ACTION:

Follow the Service Procedure steps to correct the condition by applying foam tape to the window switch bezel.
SERVICE PROCEDURE
Remove window switch bezel from door panel and separate the two piece bezel.
Install three (3) pieces of PVC soft foam tape 3/8" wide by 1 3/4" long (10 mm by 45 mm) part number 164-R4901 from the Rotunda Squeak and Rattle Repair Kit part number 164-R4900.
Reinstall window switch bezel and verify proper operation of the window switches.
WARRANTY STATUS:

Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.

Haha it drives me insane, it will vary in severity but will be there at some level for almost any sort of music/radio/cd.

It really cheapens the feel of the car, I'll be getting this addressed on my next day off. You guys are the best.