It's an easy choice, Krown is the only way to go. If it doesn't drip, it's not going to work. Both Fluid Film and Rust Check build up year after year, and trap moisture under themselves which causes rust. Krown drips off until there is a thin oil film left. I can guarantee any product that doesn't require an annual reapplication isn't worth a pinch of shit either, been there, done that. My 6 year old Mazda 3 has holes in the body, that weren't supposed to happen due to their miracle, spray it once and forget it, product. Luckily it's going to be fixed under warranty, but I should have just put Krown on it every year and not worry about it. Anyone in Canada who uses something other than Krown is wasting their money, in my opinion.