Update on this if anyoneis interested. Know there was discussion on fb page some time back. This will be my 22 month update. First application took a half gallon. Had ordered the gallon from o'reilly for around 50, sprayed everything under the truck that wasn't aluminum or got hot. Even dropped the spare and coated the steely. There is a lot more real estate under that fronty than there was my imp. Fluid film stayed everywhere through the first winter, end of this winter i could see places where the tire spray had taken it off. Between Sandy slush and mud season places on the frame had nothing left. Reapplied it today, only used a quart doing all the frame, rear end/ springs, front suspensionn inner rockers and trailer hitch. Everywhere i had applied it that wasn't affected by Tire spray it was still there. I had just a couple places showing small amounts or rust where I'd either jacked on the frame or had rocks from the tire hit it. I'm going to start doing yearly applications. Guy i work worth had his gmc done in 13 and just used 3 rattlecans to just do the frame. Its definitely more cost effective to buy by the gallon and use an undercoat gun. I like this stuff enough I've been working on my employer to start using on our trucks ( gaining)
With jameys comment about factory undercoat, didn't affect mine at all. Does say it doesn't like natural rubber so maybe Subaru and nissan use different stuff. Going to spray my girls imp before winter too