I've used PERL on 3 of our cars and both boats. I tried at first using it at about 2:1 for the tirm and it was a bit spotty or streaky. I then reapplied using at 3:1 with no issues. It did darken everything on the cars and worked wonders on the fenders, handlebars and gas caps on the boats(jet skis), one of them has a gas cap that was almost white and it's pretty close to original. One thing though it does seem to get way more even coverage if you wipe and buff. I applied, wipe off and then buff it down and put a second coat on it later( an hour or two) no issues at all after figuring out dilutions and process apply, wipe then buff off.