Very interesting. I didn't do a clean side-by-side comparison like yours, but I have a brand new brilliant silver E320 and I too wanted to try Zaino. I washed with Dawn, did not clay it, and over the course of a couple weeks I put on 3 layers of Z5 (used the ZFX so did not need to start with Z1 a/c Zaino's directions), followed by another 2 coats of Z2+ZFX, and lastly another coat of Z2 (no ZFX) last weekend. Used high quality cotton terry, and even microfiber cloth on the last waxing. It's a very impressive shine, but...

During the same time period I also did both my wife's dark blue '99 Volvo wagon and my dark green 95 Ford Explorer with Meguiar's Cleaner Wax (didn't clay either one of them). I used a $20 random orbital buffer from WalMart with a terry bonnett to remove the wax and buff. Each car was only done once, and I can tell you the labor savings was considerable. I have to take into account the fact that these darker colors are going to show a shine better, but the Volvo looks every bit as deep and reflective as the E320. The Ford was a little further gone before its waxing, but it too looked great and even though the E320 kicked that poor guy out of the garage and it is getting fouled with nature's detritus it still looks impressive.

I keep hearing that Mequiar's may not last as long Zaino's, but so far (about one month on the Volvo and a little longer on the Ford) I think I'll stick with the Mequiar's Cleaner wax on the Volvo & Ford and let time determine which way to go with the E320.