Got it in Saturday. OK I cheated. I caught up with the chaps at Detail Day and was able to see how they did it. Here is my humble contribution to the cause.
I couple of comments on the installation.
1. The factory kit attachment concepts were designed and executed by Rube Goldberg's distant cousin, Franz Heime Porsche-Goldberg. Not exactly up to Porsche's typical bullet-proof and/or over-engineered standards.
2. Wonky as it is, it does work. Unfortunately it renders the seat flaps inoperable and requires partial removal to put the top up or down. So, if you use the seat flaps a lot this is not the deflector for you.
3. Every car is different. I've seen exactly 3 installations. One car with a subwoofer box on the flaps in the down position, one with a custom subwoofer box where the cubbies used to be, and one with the cubbies removed completely (mine) - all 3 had the chassis brace installed, which makes this a very tight fit. So, you have to mod the thing a bit differently to make it work in each car.
The key piece that you have to change are legs. The rear legs will likely be too short, and the front legs are simply in the way with the brace installed.
Rear Legs
These are meant to fit into a space above the flap hinge. With the chassis brace installed you simply cannot get the angle to make that work. So you have to mod the legs. Brian used brass tubing. I used a 1/4" threaded rod and a coupler.
1. First, I removed the vinyl bumper sleeve from the kit rear legs.
2. Next I tapped threads onto about 3/4" of the leg.
Then hacksawed the threaded rod to length, put the bumper sleeve back on, fussed with the length (cut it three times), and jammed it in there. I used the area just aft of the chassis brace post. Make sure that this is a very tight fit.
You can see that the extended leg on the US-driver's side is bent a bit outboard. I did that to get it on the little shelf. You can also see that I attached the elastic straps to the bracket that I was too lazy to remove from the cubby box (sometimes laziness is simply pre-destined brilliance). Obviously if you have the cubbies still in the car that won't be an option. The suggested attachment point to the flap hinge is just silly. When you close the flap the thing pops off.
Front Legs
Remove them. You need something to take up the space of the legs on the bolt like a grommet or a bushing. I had a bunch of plumbing washers so I drilled out the hole a bit and used a couple of those.
I got a velcro buckle strap from the local Ace Hardware store, which is designed for exactly this sort of application. Thread the strap in between the front leg mounting tabs and around the brace and pull tight like so.
Finally I put a few adhesive "feet" on the brace to keep the deflector from banging the brace - they fell off pretty quickly so I'll work something else out - maybe a few strips of splicing tape.
Here are the items that I got at the hardware store. The velcro straps were a perfect fit.
Took an hour. Kentucky almost pulled it out while I was doing this.
