A couple more comments on antenna placement.  Transponder and GPS are the most susceptible to signal loss from long cable runs.  My GPS is under the glareshield.  My transponder is the back seat in my ES.  If you're going to mount the transponder antenna in the aft of the fuselage, definitely use the RG400 cable.  The "good" cable doesn't make much difference on the COM and NAV, but a big difference with the high frequencies.

 

I would definitely stay away from metallic paints.  I selected pearls and micas.  I ran a test on a metallic paint I liked, painted it on a 2' x 2" piece of plastic and held it over my GPS antenna and I lost signal.  I tested all my paints before they went on the airplane, just in case. 

 

Mike Easley

Colorado Springs