1. inside the roof

Does it do more harm by collecting more dust when sunroof is open?
Does it wash out grease on sunroof guide rail?
Will the rustproof material spot the headliner?
Can I rustproof inside of the roof by spraying the material from the water drain hole at the bottom of the car? Where are the correct drain holes?


2. engine compartment

For model year 1992, corrosion protection, such as MB Anticorrosion Wax, should be applied after engine cleaning.
If there is already rust under the hood, is rustproof like Waxoyl better than MB Anticorrosion Wax?

The poly-V-belt and all pulleys should be protected from any wax, according to the owner's manual. Can the belt and pulleys be properly masked from very fine mist of rustproof spray? Should they be removed before rustproofing engine compartment?

Should hood pad be masked too?

What about some turbo stuff, exhaust manifold and exhaust header pipe?

By the way, I think the brake rotor and pads should be kept away from wax. What is the best method to mask them?

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1992 300D 2.5 turbo diesel. 319 k miles.
124.128 chassis, 602.962 engine, 722.418 tranny.