Subject: Questions about undercarriage oil spraying

>>Up in Canada I've heard they spray their undercarriages with some kind of
rust preventative oil. What sort of oil is it? Does it actually
work?....snip

check this out

http://www.rustcheck.com/

I use another system  Oil Tech (Canada only) it's a 3 part system... I did a
commercial for them many years ago, and after seeing all the chemistry
involved I switched from Rust Check...Plus the guys I use to apply it are
really into building hotrods and custom cars... they do a super job of
spraying all up under my syncro, inside every crack and channel.... most of
the cheaper oil spray places just hire some kids during the fall rush
season, and you get a sloppy rushed job.

BUT it will ....NOT ....put metal back on.

The idea is to STOP rust, by cutting off the oxygen,
displacing the moisture, and neutralizing any corrosive chemistry.
It will slow down existing rust a lot.....
but after the horse is out of the barn....
it's a bit late to think of closing the door.