Cleaning salt and sand out of those hard to reach places...

My poor old 2010 has been subject to the ravages of salt and chloride we use hear in Maine. There are some key places you can not get to to clean out at most car washes. Behind the front bumper. Rear quarter panel wheel well tops. Both are covered by plastic so you can't get in there to spray in the winter. Truck only has 149K right now but I have no front bumper. The rear bumper rusting heavily. Both rear quarter panels over the wheels are almost through. Was going to cost so much to replace these I just bought a new 2021 instead.
So how are you guys getting to those hard to reach spots? I hate to spend couple hundred a year getting that spray on stuff every year. Are you removing the plastic panels? Drill holes in it so I can get spray wash in there? Moving to Arizona?

 

It’s not easy but you can get most with a pressure washer if you’re willing to get wet. Front fender liners come out easy enough. The rear, if you take the spare down you can get at it pretty good. Then once it’s all clean spray the hell out of it with Amsoil MP HD. If you do that in the fall you really don’t need to worry about underneath all winter. Just rinse off best you can. Then in the spring give it a good clean.
I filled a lot of cavities,(doors, rocker panels, tail gate, etc) anywhere water could sit,with 3M cavity wax. Get the wands you can put in the weep holes. That part is super easy.
Just don’t use any sort of rubberized undercoat.

 

The annual rust proof pays itself, most well known ones even have warranty against corrosion if you apply it annually since the car is new, such as Krown.

https://www.krown.com/en/warranty/

I've seen guys with 2nd and 3rd gen Ram with mint frame and bed that has been krown'd since new, just watchout for guys that are drill happy.