XL-18 can be purchased through Ted Britt Ford Chantilly Va, cost out the door $24.08.
I have installed the .91 oz bottle and will report back later after I can evaluate if for a few days, etc.
Do you know if they have it in stock? Or do you have to order it? I'm only about 3-4 miles from there (that's where I bought my Mustang). Maybe I'll swing by this week.