Hey guys I just did a DIY rustproofing yesterday.
Rust Check - red (more oily to flow into crevasses)
Rust Check - green (thicker foam doesn't drip)
the above from Cantire or
Gutter guard (home depot)
I used alot Rust Check red to allow it to flow into all areas
Areas to cover:
Door panels bottoms (drain holes). Spray rust proofing into all drain holes or if you are inclined to take apart all the door, even better.
Trunk lid (2 drain holes) drainage gutter and bottom trunk edge (under latch trim). This is the infamous rusting area.
Hood/windshield drainage gutters
Rear fender wells
Rear shock towers and bracket inside the trunk (i didn't bother with the inside)
Rocker panels (back of front tires)
Try to do it on a clean car or you will be protecting the dust and dirt from your next carwash but be warned that you will have have overspray all over the car and will drip all over your driveway or garage.