its called a corona arch...happens with high voltage and moisture ... i saw T-Bird have one all the way up and down his antenna in Little Rock Ar. a few years back .... it was 10 times bigger than this video... but hey its still freaking awsome looking... yea thats Tbird in the left "lane"... u got to be crazy running AC Sky .... so much RF running thrugh you ... and all the high voltage inside your mobile .... i have seen tubes arching before and look like a lighting show inside this one guy's sub.....