Although I will probably live to regret this, here is a few pics of the extender I made for my '06. I installed it the same way as my '04, with SS hardware, 10-24 Button heads, washers and nylocks inside the fender. I put some outdoor double sided tape at the top of the extender to seal the joint to keep water / mud from seeping through.
Here is the pattern I started with. Took a couple test fits to get the right size. If I did it again, I would make it 1/4" longer and 3/8" narrower.
I found some pre-formed ABS about the same thickness as the fender. You could match the paint, but in the interest of time I chose basic black. I used Krylon "Fusion" for plastic, satin black. Picked it up at Wally world for under $5.00. Followed the prep directions on the can and it went on very smooth. The stucco pattern was in the plastic I found.
Another shot showing the relative fit into the cowling area. IF I could have curved the ABS to better fit the tire radius the extender could be a bit longer.
Finally for an idea how much clearance I left while clearing the cowling...
The extender definitely cut down the amount of crud on the front cowling. However in this case longer is better.
Enjoy
--G