I am in Canada too, my last car I did the rust proofing with Rust Check, they needed to drill holes in your car and sprayed the rust proofing mist inside of all the panels. It was EXTREMELY messy, because the excess chemical (oil based) will drip on your driveway for the following few days, very annoying. But I heard that this method is the most effective, there are dripless formula you may want to try. Either way is better than not doing anything if you decide to keep your truck for more than 10 years. These guys want you to go back for reapplication EVERY YEAR but for me I only did ONCE and when I sold my car 8 years later, there were minimal rust (at least the buyer didn't see anything obvious), I think that worked. Compared to another car I had before (Honda Prelude) without rust proofing, rust started on the wheel well badly after only 6-7 years. For my new RL, I am on lease... of course I am not doing it.[/QUOTE)
I to will vouch for Rust Check. Did my 87 F150 every second year until I sold it in 2006. Hear is a picture of my truck when I sold it. Don't worry about the dripping on your driveway after the rust check application, the oil stains disappear in a few weeks.