Rustproofing?

[09passioncoupe]

I would not worry too much about it due to the plastic body and other plastic components. I would be more concerned about the frame. If you look under the car from the rear you will notice the frame ends (di-dion tubes) are open at the ends. If I lived in a area where salt is used in the wintertime, or near a body of salt water, I would cover the ends of these tubes to help prevent salt spray from entering the inside of the frame tubes. Smartmadness.com and other vendors offer these covers in black and stainless steel. (I am not associated with Smartmadness or any vendors.)

[chieftmc]

I remember reading "somewhere" that the smart IS rustproofed at the factory with some kind of "wax" based rustproofing; so no need to any "additional" rustproofing.

Not only is it not needed, I believe I read it is NOT recommended as it will compromise the integrity of the factory rustproofing!

[SubSlr88]

Problem with capping the Didion tube - it may trap moisture inside and increase the probability of rust~! If you cap it make sure it has a drain hole and/or vents to allow moisture to escape. Most folks just cap them to look better, not keep water out . . . And the whole frame is powder coated prior to assembly - I would think that should pretty well eliminate any rust problems there.
My $0.02 . . .