I've been a avid Z user for about a year now on my silver 330i. I am happy with the results, but decided I would give the Klasse system a try on another car. Yesterday I applied 2 coats of AIO to my mom's silver GS300. That process was pretty painless, and the results were ok. Then I I applied the SG. Instead of just applying it to one panel I applied it to the whole car (like I do the Z). BIG MISTAKE. I didn't really give it but a couple of minutes to dry, but it was a MAJOR pain in the but to remove. I couldn't believe how hard I had to rub to get it off. I'm so use to the Zaino, and this was horrible. I ended up having to apply another coat of AIO just to get the SG off. Maybe I did something wrong. Maybe I applied too much. I'll never do it again though. Zaino is sooooooo much easier.