Clarion is famous for defective High End Units.
I practically had to go to war with them over a Joyride Unit I bought a couple of years ago. Brand new, Picked up EMI like it was going out of style.
Two months later, they finally conceded that it was the deck, and agreed to send me a new...
With all respect, I had the same question when I installed my Clarion Joyride in my SC. I will try to sum up what I was told: "you do not want to reverse the polarity on speakers. The main reason being that it will make them sound like crap, because when the speaker is supposed to move...
No worries.
All you have to do is tap that blue wire to a fuse that only comes on with the Ignition. You don't have to worry too much about current draw, as it is MINIMAL. All that wire does is send a positive reference signal to the amp, telling it to turn itself on.