Early days for me with around six months use. Front doors used regularly but rear doors less so. I am hoping that with plenty of silicone or graphite lube, and regular use of doors, the situation will improve and no mod's from the dealership required.How often do you have to re-apply? My front doors seems to be freeing up with use. But the rear back door which faces the prevailing wind and rain is becoming irksome. Yes I know I'm now parking it the other way round.