I think i might try that motor oil trick. My grandpa said they used to do that on the chains on his sanitation truck before they got in trouble for it.

 

The motor oil trick is good if your spraying it on an already rusty surface. Thin oil like that will "creep" (absorb into rust like a sponge). Used oil is very messy. There are other undercoating/ oil spray products that will adhere to the car much better

 

I park it for the winter in the garage