Subject: How does electronic rust protection work on automobiles?

There  are  several companies that  advertise  an electronic rust protection for
use on automobiles.   I don't  understand the explanations  despite that I've
had   highschool  chemistry,  physics  and I've read  about  electroplating and
metal cleaning  and I've been employed  as an electronics  technician many 
years. I learned about  batteries and ions, anions etc.  The  electronic  rust
protection doesn't make  sense to me  and the equipment  advertised is very
expensive in some cases.

Re: How does electronic rust protection work on automobiles?