Christian, I don't recommend doing away with the center dash vents. I had a vacuum leak that stopped my center vents from staying open. And when those vents wouldn't stay open, it was just as well to turn the a/c off. In Florida's humid weather, I have found that the door vents are mostly only good for fogging up the side windows at night. Even trying to close them off doesn't help. I'm planning on cutting sponges to fit to stick in the door vents (to put in the space while the door is open) so that I can stop my side windows from getting fogged up so bad. It makes the side mirrors useless, and I have to roll down the windows to get any side visibility. And YOU want to rely on these to cool your car without the center vents? LOL. By the way, the windshield defrost vents are great for fogging up the windows and do little to de-fog them. I suppose they were designed by yankees who think that moisture only accumulates on the inside of windows. I think a better idea than doing away with your dash vents would be to custom make a new center console that extends a few inches higher over the dash to make room for a second unit. If your proposed electronics setup is in two pieces, then you could mount one over and one below the dash vents. If what you have is a one piece setup, then perhaps you could move the dash vents up higher. They are connected by rubber/plastic looking flexible duct. Possibly a new custom duct could be made to direct the air up higher without too much restriction to air flow. Then you would have your vents on top with a double height radio mounted underneath. If a custom duct would restrict air flow too much, then perhaps modifying the manifold behind it could eliminate the double elbow. Let us know what you eventually decide to do. It sounds like an interesting project, but it all sounds like a lot of work. Walt Tampa, FL