My 4WDs have always been washed 2x per year=once before winter and once after winter. The Blue Beast (2019 SR5 Premium) is getting washed today after a 3-week trip though the SW. Had to use 4WD to get through mud holes created by early monsoons!
For gawd sakes, it's a truck!
BTW: There were several 4Runners in the Visitor Center parking lot. One woman pointed at us as we left (Theirs was also Nautical Blue) and all turned around to stare at our mud-covered monster!