Seems like every LSP stops beading after a car gets thoroughly dirty, wondering which LSP would be reliable to last through rain and dirt and still bead strong for at least a few months.
Even after driving in the rain twice, paint covered in road grime, MPL still beads water. After washing it looks like I just applied it. The water resistence is not diminished by being dirty, just the dirt breaks the surface tension of the waters surface therefore breaking the bead. The protectant is still under the dirt doing its job.
I currently have Auto Finesse Desire on my car. Beads insanely well and is rated to last ~6 months. By far my favorite wax in my collection