It's been a year since I last Zymoled my Atlanta Blue Z3. Although it was still shiny and didn't accumulate dirt, I figure it must be time. With the washing, drying, HD Cleansing and hand waxing, it took 4 hours. The results are spectacular. The painted surfaces are like mirrors. I'll never even try anything else(cause I have enough for 10 years at this rate). Most important, make sure you wax around the windshield washer nozzles. If you don't, dirt will accumulate around them when everything else is clean. It's very annoying.