I just wanted to close the issue. Yes, it worked.
It looks like mine was an inductance issue on the rca cables. If they go ANYWHERE near the single din space the h2a is in, they generate alternator whine. My guess is there is something else back there that pumps out a good amount of noise.
Here is the story: Went to circuit city and purchased a ground loop eliminator. Got home and pulled the radio and the H2A to expose all of my wiring. Hooked up the ground loop elim between the h2a and the radio, but it kept on humming. I was resigned to just disconnecting it and bringing it back when I put the eliminator on the din shelf where the radio normally goes, when the sound went away. I disconnected it, rerouted the wires, plugged it back in and shoved it behind the radio. Works fantastic now.
So now everythign sounds great, but I experience tons of dropouts due to the antenna placement... Being as I have a boxster, there are only a few places you can put the antenna on the outside, and none of them look good. So I just got some heavy duty velcro, put it on the top of the antenna, and attached it to the underside of the plastic waterrunoff tray between the hood and the windshield. (Look at your car for the plastic between the windshield and hood, thats what I am talking about.
It is surrounded by metal surfaces, but it does not rest on the metal itself.
Fully hidden antenna install and it works great. No dropouts except under a few long bridges.