Undercoating floorboard

I dont know if this is in the right section, but anyways. Has anybody removed there carpet and undercoated the floorboard and then put the carpet back on? I ask cause i pulled up the door trim (the plastic trim on the body under the door) the paint scrached it were the trim snaps in and there is little spots of surface rust in those areas. So i was thinking about taking out the carpet and undercoating the whole floor board. Even though the spots are little. I rather undercoat it before it gets to hard to prep. So i was wandering if anybody has done this if so any tips? And i did search but didnt find what i wanted.

 

i did it years ago to my last truck. after a number of buffalo winters the carpet was getting crapy and pulled to wash. thats when i noticed some surface rust on floor board. cleaned it and shot it with some spray undercoating. looked a couple years later and it still looked fine. I should probably do it to my new truck.

 

I've also done this to a couple of my previous trucks.
Living in Canadian harsh winters, no matter what you do, it still gets wet under there.

Mind you, on my new taco, I have the weathertech mats... Some minor wetness might still creep it's way under there, but not nearly as much.

If you are going to pull the carpet to apply product, use POR-15
It's incredibly tough and hardens like a rock. Lots of car restoration guys use it.

 

I was probably going to use Chassis Saver. Im undercoating my frame this fri. And then i want to undercoat my floor board later on, and my underbody is already undercoated. So i should be good to go!