Alternator Whine after amp/deck install

[BluBYou]

I installed a Soundstream amp and Alpine 9856 deck my 03 Boxster, and have been getting a lot of alternator whine from it. I have tried re-grounding the deck to the chassis, regrounding the amplifier (I have it tapped off a bolt in the front trunk).

Two weird factors about this -- when I have the key in and I push the gas pedal in, I can hear somewhat of a whine from the speakers, and it varies with how far I push it in. Strange. Also, when I plugged in a ground loop isolator to my RCA's, and the whine got WORSE.

I have the amplifier mounted in the front trunk, and the power cable runs from the battery down the passenger side of the front trunk and right into the amp. I don't think there is a way to separate these and keep the power and the inputs from running separately when installing it here.

Any advice for me? Help!

Also -- which antenna adapter will I need to plug into the stock antenna? I can't find one locally.

Playing music loud to not hear the whine--Matt