04 Jetta aero pix
 

Here is a rough approximation of what I'm tentatively considering on my car. I've already got the front grill blocks except for the sidemount intercooler grill and the bottom below the bumper.

Keep us posted !

B.T.W. ( Do you weld ? )

Looks like a plan, I'd like to see what ya do with it, :)

Yeah, I've done my share of welding. I've got a rough template for the wheel covers but I'm still conjuring up ideas for holding them in place. I've also got a good idea how to get the mirrors off too.

'04 Jetta tail extension
 

Kafer65,I took some clear vinyl,laid it against the computer screen,and traced the outline of your proposed mods with a Sharpie.When I put a protractor to the image,I got about a 17-degree angle,from where the roof begins to drop away,and where the boattail ends.I couldn't actually see the end of the tail,as it's cropped off in the image,but I was guessing that it did not project much more beyond what I could see.Anyway,I believe that if you raised the top of the tail and projected straight back,horizontally,the tail would terminate on an imaginary line intersecting at a 12-degree angle with the roof.I think there's a consensus among members at ecomodder that you wont be able to push an angle any steeper than 12-degrees without separation.If you can make sense out of my post about Tiger Woods and Cinderella it will also provide some guidance on workable rooflines.

That's very interesting. That would be an elegant way to tie it all together. The picture of the EV1 with the added tail is what comes to mind.
I made the picture by eye to be a rough approximation of 12 degrees or slightly less. I intend to terminate the cone about 55 inches or less from the rear edge of the car for my convenience. That's why it looks like it's cropped off of the picture. I want it to be simple to construct and easily reversible.

you might consider some sort of turbulence generating material in front of the roof drop.

EV-1 tail cone
 

The EV-1 boattail would be a good model.I have a video from General Motors showing their land speed record runs at Fort Stockton where they set the records and it shows the installation of the boattail and the subsequent runs where the car is breaking its own records for the flying kilometer and mile.Fun! There's is made of sheet aluminum with inset rear bulkhead,and faux tailights.They cleco'd it on,and then its shown taped up.I don't know if they pop-riveted it on or what.I believe the tail was good for an additional 5-mph,pushing speed from 178 to 183,so you know its effective.