I JUST de-gunked mine last weekend. It is due for a full polishing and then ceramic (once winter is over), but I couldn't take it anymore.
I gingerly washed it... had to do wheels 2x, once with ECO all-purpose THEN wheel cleaner... and after a long, long rinse... did a "pretreat" with diluted rinseless, and two layers of foam before carefully washing. It paid off... came out nice, felt baby-butt smooth, and wasn't as thrashed as I expected. But yes, I HATE WINTER