What to do?/parcel shelf

I am trying to decide what will be the best way to install a set of 6 1/2" components in the parcel shelf where a set of factory 6 x 9's were.

The parcel shelf is a piece of flat metal inside the trunk...the factory 6 X 9's were installed on the bottom of this.

Between the metal parcel shelf and the piece that is perforated to let the sound through to the interior is a air space of almost 3 inches...and the perforated piece was flimsy..so I foamed it(polyurethane foam sealant,minimal expansion) and this stiffened it up quite well.

I can cut a hole in the top where the perferations are and drop the componets in there, yet this will leave them exposed to thieves,and the glaring sun,leave a hole in my car, yet may produce the best sound quality.

Or I can mount them on a piece of MDF (I have some 3/4 " thick) and then screw the MDF piece on the bottom of the metal piece of the parcel shelf( I also have one of those Foam 6X9 speaker baffles that i can staple to the rears of the speakers to simulate a enclosure...doing it this way will hide them from thieves and the sun that glares right through the rear window(I have legal window tinting,it still shines pretty heavy through there) Yet this way may kill SQ since it has to go through the perferations.

My question is basically what a pro would do and do you think it will kill the SQ that much playing through those perferations?

Also I have not done anything yet,so if you have any better ways to install this..let me know

Thank you!!, I will give it a try... !!

Hey I will put the pics on a webpage and have a link to click on when I am done. The door buildouts took two weeks yet they turned out great,I almost hope the MB quarts require a different hole than the infinity reference series when I get the MB Quarts in the mail, because It will give me the incintive to redo those door mounts(what a pain that was!!!) ,and I will get the angles right for a better front stage this time. I am still going to build the amp rack, have a couple ideas for that, such as finally finding a use for those mini red gas tube lights that cost me 75.00 a pair ( that I bought for a motorcycle) and never could find a good spot to place them.  I was thinking some plexiglass holes and place those underneath the amp rack. ( that will look good I think with two RF power amps sitting there, all the wires hidden)

 I'll send that link when it is done, I have been working on this car audio install for a total of three months, and it is about halfway there.

Expect more questions :) I truly appreciate the help I have gotten here.