Man I hear ya. Just due diligence in pressure washing the underbody and keeping a close eye out for small newly forming spots is my strategy. I already nuked the hell out of one spot, the driver's trunk drain, and don't see any others yet, but I've only had the car 9 months. I got a rolled up blue paper towel and spread some axle grease on it and ran it up in the jack points, then installed plugs. Rockers look good on mine, PO went ape***** and coated them with something not very OEM but it's thick and hard and glossy black. These cars will rust, mine will rust, yours will rust. Everything rusts. I saw a late model Jetta with paint swells on the rear fender.
I like the FluidFilm idea and will try it soon as I get a round tuit.

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'02 BMW 325i
'85 300D 450k
'93 190E 2.6 170k(killed by tree)
'08 Ducati Hypermotard 1100S 6k
'06 Ducati S2R800 14k(sold)