I know what you mean about the sore arm. I have one every weekend, 2-3 cars to wash and I usually use detailing spray on mine. Have you tried Zaino? Its one of the easiest polish products I've ever used. It leaves no dust and gives you that nice wet look. Used it on both of my black PT's.
I'm one of those who has painted the inside of the exhaust tips black. Took about 10 minutes and it really looks nice. Black Barbeque paint form Krylon is what I used.
BTW your car looks real nice so it was worth the sore arm I'd say!

Pat