Yo Steve, I think he really has never gave much thought to it. I know I never did until recently. Although he said my truck looked OK, it is an Expedition after all. I mean, how good <em class='bbc'>can[/i] they look? This guy is very intelligent, and he was intruiged that the Zaino was not a wax but an acrylic polymer. He was not impressed by the number of coats I put on, however. I think, in his book, if you can get good results with one coat of something then that is better than getting great results with 5 or 10 coats. As far as his comment on how long the wax lasts, if it still is looking good to him I guess he figures the wax is still doing it's job.
I remember using a good carnuba paste wax (2 coats) on a brand-new '94 Mazda B3000 I had a while back and it looked great for almost 2 years until I sold it. It even beaded water somewhat. But I hardly ever washed it if I remember correctly - maybe 6 or 8 times during that period. And it (mostly) was parked under one of two carports day and night. I still have that wax somewhere. I think it was Meguires. That truck got keyed the first week I had it. All the way down the passenger side, very deep and nasty. With a beer bottle cap, I think. Really torqued me, and after that I lost all desire to keep the thing nice. Some people... When I sold it the keying cost me about $2000, I sold it with 11,000 miles to a used car dealer. I had an add in the paper and not one call for 6 weeks. Changed the add several times. I think my mistake was that people saw the low mileage and assumed there was something wrong with it. The dealer repainted the truck an ugly reddish-orange color (the factory paint was deep red.) A few years later a good friend's son drove up in my old truck. He didn't realize it had been repainted. He bought it from another dealer somehow - maybe the guy I sold it to sold it at auction or something. He liked the paint job - trust me, it was hideous.
