Acoustical Fabric and Paint

I'm looking for information regarding acoustical fabric and how paint (most likely spray paint) would affect it's acoustical transparency.  Obviously the paint will affect the sound.  Is there anyone out there that has done this before or might have an idea on what the expected effects might be.

The concept:  I drive a Scion xB and live in Brooklyn.  I want to cover the rear hatch area, but not muffle the speakers back there.  My idea is to build a frame (still debating materials) and stretch acoustical fabric across it to create a cover for the speakers and thus make them less tempting to potential theives.  However, black fabric over that large of a surface seems dull.  I want to have one of my graffiti artists friends paint it.

So... any thoughts on how the spray paint might affect the acoustical transparency?

It will also flex with the bumps and flake off. Use light strokes with the cans.....LoL. You should get away with some paint....just NOT too much!!

Do a test hunk of fabric first....It's cheap.

Grille cloth/acoustic fabric will not affect the sound quality.

For paint, get a hold of someone in the silkscreen business. That will give you an extremely flexible/durable graphic that will not flake off while you are hitting it hard.

As for the vibration that occurs with hitting them hard, get a hold of a piece of grille mesh large enough to cover the area for the subs. If you can't find the actual screen, you can pseudo one from a piece of wire mesh from Home Depot or Lowes. Or splurge just a little bit to get that prepunctured sheet metal. Get the one with the largest holes in it. Stretch the cloth over the metal/mesh and fold over the edges gluing the backside of the panel.