Best rust treatment/preventer

[alfantastic]

I'm after a rust treatment/preventer spray to put on my cross member and other slightly rusty components. It's gotta be very light and free flowing, no paint type stuffs and in aerosol form.
I've been using WD40 so far, but am not convinced this is the best stuff to use. I'm not trying to halt rust completely ... difficult if nigh impossible ... but trying to prolong the life of existing components. After all, most of us buy Nissans for cheap and reliable motoring.
Would a good quality penetrating oil, like Plusgas, work????

 

[rowdy-GTi]

The only real way is remove it, strip, and paint.

 

[mera red gti]

the good stuff is think however can be sprayed on, see my thread. i was lucky to have fully under sealed my car before any rust set in. its a messy job however a must on our jap cars as the came with zip all underseal.

click

david

 

[wraith]

Hammerite Kurust to kill the rust then Hammerite direct to rust paint and waxoyl on top?