Being born and raised in the rust belt I have tried just about all the rust preventative systems out on the market on all of my daily drivers
The latest one I have used seems to be the best in my opinion which is
https://www.woolwaxusa.com/Undercoat...r_ep_43-1.html
It has held up quite well thru rain and snow and still is “sticky” to the frame and underbody of my truck
I have a local distributor who applies it for me and am quite pleased with the results