Almost anything.....
I have 4 layers of BFWD on my black truck over a 4 week timeframe that I didn't drive it. After driving it to work for 4 days the bottom half of the truck has not protection after washing it. No beading; No sheeting. The water just clings...
I have and use KHGS, Menz PL, Megs NXT2.0, Max Wax, Fuzion, Banana Gloss, DG AW, Colli 845 just to name a few.
I will say BFWD looks great but if I or clients can't drive their vehicle and maintain protection for 2-3 months then it will get traded or sold. I feel is is far to expect 2-3 months of durability from a sealant.