I left these pieces out in the sun for about 4 hours. To Liu Bei's point, it removed about 99% of the discoloration. There were a couple spots where I didn't spread the cream, like the top of the seat backs near the head rests, but otherwise looks very good in person. I'm not opposed to using the liquid, but all I had at the time is the cream version. When I first learned about the process I saw it done with the cream so that's what I bought. Didn't know the liquid existed at the time.