I was talking with a wholesaler who is searching for a Cavy for me (as discussed in the Lounge) and he recommended a professional product that all the local dealers use. He said it will typically stay on for several weeks (assuming no rain, snow, etc.).
It'* called "Super Stuff," made by Professional Car Care Products. They're out of CA. A local retailer sells it for $20 a gallon. It'* a silicon based, waterproof protectant. Here'* the link, check it out:
If you nose around the website, you'll find that they really cater to the industrial auto detailer.
I bought a gallon and poured some in a squirt bottle and sprayed it directly on the tires (didn't dilute). They look wonderful!! The best part is that it doesn't stain the driveway like Armor All does! I'll keep you posted over the next few days with my results. Time will tell!