well basically i have the roller in one hand, and the foam "paint brush" (in the pics) in the other. you have to work fast because the paint becoms non workable in about 10 mins. so i do one pannel at a time. it goes quickly, takes about 1 hour for a coat on the whole car, i've done 2 coats in 1 day no issues, it dries fast. but for wet sanding i wait overnight. basically in the rain channels i would use the brush and cover it completely, then use the rounded end of the roller and go over it, it's hard to describe, u just have to be paitent and expirement on one pannel like the trunk lid and do the whole process and see if your happy, it's easy to bail the project with only having to re-do the trunklid if you can't handle it or have one of those "what the f*&k am i doing" moments!!!. I also load the roller up quite heavily, then work it until the roller does'nt have so much paint in it and do the detail work after. once you spread the paint wait a minute or so and then just really gently run the roller using only the weight of the roller, on the sides just use very very light pressure as if it were the weight of it. How you thin the paint is critical, i have not had one paint run on any of the cars i've painted. To give you an idea, you really only start to have full coverage to where u can't see any body work or underlying color thru the paint until the 3rd coat. Oh and i strip the car of all chrome, bumpers, rubber, door handles, trim, ect...nothing looks cheaper than a car that's just taped!!! That's the best i can explain it!!