Ziebart if they still exist.

http://www.iboats.com/CRC-Marine-Heavy-D...1--view_id.5226

http://www.eastwood.com/ew-heavy-duty-anti-rust-32oz.html




For the CRC stuff I use that with a spray straw and inject all the door bottoms, leading edge of the hood and all the other nooks and crannies where rust starts. The eastwood stuff I have used less but still like it as well for the bigger areas like inside the rockers and internal boxed structure, it requires a spray gun of some sort which I have but its still messy.

Undercoating over clean surfaces is ok, you just gotta keep up with it and of course applying it over rust is a big no-no. I just use the 'regular' version https://www.rustoleum.com/CBGProduct.asp?pid=364


For bare areas wire brush, wipe clean and lay some of this stuff on http://www.vhtpaint.com/products/epoxypaint/ Its not really epoxy but it does dry nice and hard.

For all the above products I'm pretty generous on how much I use for just my car, I pound the stuff on every year and hope for the best.

Edit:
Bar and chain lube is good, might stay kinda drippy though. I have done the used oil spray on some old junkers, its going to stink and stay stinking for a long time. Not something I would use on a brand new car. The crc and eastwood will stink for a few days until the solvents have evaporated and then there odorless.