There was a lot of discussion on the PT Cruiser forums about hypergounding a few years ago. A kit is pretty to assemble from good 4ga audio cable and gold ring adapters, so I spend a whopping $7 and got enough parts to do both my PT and our old Camaro. A lot of speculation centered around the worse the grounding in a vehicle is, the greater the potential benefit. Plenty of guys with fairly high end aftermarket sound systems noticed an improvement in certain areas after doing this, quite often in simply preventing the headlights from dimming when pushing these sound systems pretty hard. A few guys claimed noticeable gains from their butt dynos.

So I hooked it all up on the PT, making contact at several points. Nothing. OK, so maybe the Camaro could benefit since it's an older car. Nothing. Zip. Nada. Zilch.

Meh, $7, no great loss.