Originally Posted by Too Stroked

First, you don't want to spray it on the exhaust. It'll burn right off, but it will be one hell of a smoke show. The fact that it burns right off is why you don't want to waste your time there.

As for areas to get, remember, rust generally starts where water and road salt get into a semi-closed area, then sit. So, any closed area such as frame box sections, inside the rockers, down into seams, etc. is very important. Pull the access panels at rear sides of the vehicle and spray down into the seams along the wheel well lip and bottom of the quarter panels.

Yes, you can spray the inner door areas by using the drain holes at the bottom of the door, but make sure you spray both forward and back to make sure the entire bottom of the door is covered. Also make sure you don't spray so much in as to block any drains. Same goes for the hood and hatch. Speaking of the hatch, the latch and striker mechanisms are also important to hit.

One other area many people forget is the spare tire lift mechanism.