remember most have stated UTTG dont work well at darkening the trim, works great to protect but its darkening abilities are not the best from what ive seen and the reviews ive read. me personally i use meguiars ultimate protectant/ultimate black does darken, and protect. if applied correct ive had it last 4 weeks or more with little rain, only spots that did lighten up is where water drips after a couple week. still looking for a perfect trim dressing that will work on grey and black trim, im thinking solution finish as from coreys review really has me sold on this stuff and he used it on grey trim(his reviews are the first i read as hes awesome with them so awesome it makes me not do many reviews because i cant compete with his quality of reviews!)