To be honest, I tried reading this site, but knowing that this kind of things are allways enormous bullhsit (excusez le mot) I found difficulties getting through. There are several known terms like 'polarization' and 'double layer' and they are only applicable to two electrodes in an electrolite. Since damp aer is no electrolite, and several rain drops do not make one that covers both electrodes either, you can take my word: don't believe this bs.
If you want to do something, a better paint or even a Zink layer underneath a good paint, is fine. But of course you will have to repaint your car then..

I agree.

I think I understand what they're saying; that if you apply a pulsed negative charge to the car or engine body that you inhibit natural galvanic corrosion. But does their product take the charge from the battery? There isn't enough information to make a complete assessment. I'd be interested in detailed, comparative corrosion tests. Also, if they draw from the battery, does this drain the battery?

gvh is right, they don't work.  On the surface they look good, but they are fundamentally flawed.

My experience is that anything that works can be explained in a layman's language. This company / manufacturer appears to confuse the issue by a jargon of chemical and electrical terms but still fails to communicate completely the theory behind their so called ultimate invention. If this were true that most of the vehicle manufacturers would already have employed this technology in order to gain a competitive edge against the competitors.

I think theoretically it sounds good but practically its nothing other than a sophisticated way of selling their ……….?????????

I personally don't think that this system will prevent rust in an environment that was sufficient to cause rust.  There may be some very minimal protection provided... but I doubt it would be significant enough to be visibly measured.

There is a method used by contractors to protect iron pipe.  It involves attaching a magnesium (or maybe zinc also) core attached to a conductive wire which is attached to the iron pipe.  The whole apparatus is buried with the pipe.  Instead of the iron degrading on the pipe, the degradation occurs at the magnesium core.  The lifespan of the core is dependent on the size and purity.  Of course, both objects are surrounded by earth which acts as the medium. (electrolyte?)

Magnesium strips are also used on metal boat hulls to prevent oxidation in salt water.  In this case also, there is a medium (electrolyte?) of salt water on both objects.
Perhaps a magnesium strip or block located in certain bare metal areas could serve the same purpose in your application?

This question comes up periodically here and on the finishing.com forum.  Basically, these companies are in business to make money per P. T. Barnum's dictum: "No one ever went broke underestimating the intelligence of the American public."

1) No electrolyte, no cathodic protection circuit.
2) Auto body is already 'charged' since connected to the negative battery terminal.

See
'Electronic Rust Prevention System'
Thread338-56317
and
'Rust Prevention [Australia]'
http://www.finishing.com/198/90.html