Contour Enthusiasts Group Archives Forums Modifications Audio speaker problem

It's not that hard really. Use foam insulation tape from the hardware store (sticky on one side) and press strips of it to the back of your license plate. Then use four screws instead of two. This is what I did and it works great!
You also need to address the flapping air vent valves in the trunk of you car. They are located on the left and right side of the trunk right behind the cloth covering where the vent slits are cut. I used a piece of folded up cardboard to force them open so that when the woofers move in and out the rubber flapper valve doesn't make a slapping noise.
Last, look under the car where the spare tire well is and you will see some black box under it with tubes coming out. This is some portion of your fuel tank vapor control system. The tubing needs to be tie strapped a little tighter, and you could put some foam tape around the lines if necessary when your strap them better.
I also took my rear bumper cover off and put more foam tap along the 'rub-spots' on the black bumper that is underneath the cover so that if you have heavy bass it will cushion any vibration from the bumper cover.

Next, In my trunk lid I used a spray 'expanding' foam to squirt up into the holes of the bracing. It works awesome to make the trunk lid less resonant BUT you need to leave the trunk open about a day if you use a lot of it so that it can dry. Be sure to tape plastic sheet in the trunk wherever that stuff can drip out for a few days afterwards to catch any stray drips.
Also, add small squares of dynamat to open panels on both the trunk lid, spare tire well and the rear deck in the trunk.
Under the car you can tap any piece of flat metal with your fist and hear a change in the resonance. Louder means you might use a small couple inch squares of dynamat.
LAST: after all the dynomat pieces that you want to add are on the car, use a can of rubberized undercoating to spray all the open areas of metal like the spare tire well and even the floor panels.

There is more to do inside the car as well, but you asked about the trunk and stopping exterior vibration and noise.

If you take this same amount of effort as you go through the car installing stereo equipment, you will end up with a car that is dramatically more quiet on the road than your stock SVT contour. I did this and much more and it is a night and day difference when you finally go back and ride in someone elses contour.
My car right now is quieter than many new cars.

Oh yeah, look at my webpage and look at my stereo section. I have 4 tens in the trunk and it doesn't rattle.