Fluid Film is a great product. I buy it in the 5 gallon drum. It comes in regular viscosity, and the extra heavy grease like AR product. The regular viscosity also comes in spray cans. The result is a nice thick product, which still creeps into the crevices and seams. My own mechanic uses a propane tank, with the top cut off, and installed a heater in the bottom. He usually sprays HEATED Safety Kleen anti corrosion oil. When I come to his place, I spoon about a gallon of AR into a pot, and heat it up on the stove. We mix 50:50 AR with anti-corrosion oil product, HOT, and spray it on HOT. I get all my 6 cars done, for 300$ - all surfaces, inside rockers, inside doors, etc. the works. I have a 1995 Dodge Colt, driven all year in salt and snow, completely MINT condition. I never wash it, just let the rain do the washing, and spray it once a year with oil/Fluid film. Krown is also excellent, but is very thin. I alway get all my new vehicles done with Krown, so the holes can be drilled, and as a "primer" coat. Then, sometimes I will get it down with Rust Check, which is a little thicker. The same year, a few months later, I take it to my own guy, who applies a nice heavy layer, about 2 l for a subcompact, 3 l for fullsize, and 4l for a truck. So, the first year, my vehicle gets 3 oil sprays, and after that just once a year.
This way, the vehicle will never rust, and disassembly is very easy, because the nuts and bolts come apart really easily, so I save on body shop, save mechanic fees, and save on not having to always keep buying new vehicles. The 300$ I spend annually on 6 vehicles, is worth in "value" $3000, probably.