Dealer installed louver option on ZXes.

I have had them on a Z with no rubbing. I bought a ZX that had them and there were no signs of rubbing anywhere except the rubber feet that sit on the glass which would be normal. I have seen some that don't fit, they look like they came from another car that is "close" in shape.

The dealer louvers should fit very well, if they are true dealer item.

Maybe there should be rubber washers at the deck that raises it just a tad. Otherwise I'd run a strip of plastic laminate along that painted part.

Not sure which type is being discussed, but the type I have uses a 1/4 20 thumbscrew at the bottom of the hatch with a nutsert in the hatch. It has a rubber strip along the verticle side. No vibration issues, but mine were bowed slightly and the rubber doesnt make contact. Soft aluminum

Sounds like it. 4 of these screws along the bottom. I guess you can see daylight along the seal of the sides.

Yes 4 screws at the bottom, and yes I can see daylight on the side edge. You could simulate the bow by moving the mounting points closer together. The only way I can see to do it is at the top mounting hinges, maybe elongate the holes there, and hold it compressed and tighten. I like the spacer idea. Seems faster.