Lee:
I prepped Liz's Saab with Menzerna Final Polish II to polish out any swirls/water spots/marring. It left a squeaky finish and I proceeded to spray on Optimum. For the hood, I think I used 4 squirts. You apply just like a QD...spray and wipe. It cured fine (no rain after 24 hrs).
After about 4+ hours, I noticed the look began to get wetter and a bit deeper as the polymers set up and crosslinked. The day after, the paint looked even better! 12-24 hour total setup time. So initially, no real enhancement, but after 4+ hours you begin to see it.
I'd say about 4 oz (their sample bottle) will do 10 full vehicles. If each vehicle is prepped well, a total application should take ~5 minutes.
For durability, the Saab sat outside 24-7. This was also through the heaviest of pollen season (May-July). The car sat under some heavily sappy and pollenized trees for this time. To compare, I used NXT paste on the trunk.
Both the NXT and Optimum died around 2.5 months (probably more like 3.5 - 4 months in a friendlier outdoor climate). The vehicle was washed every 7-10 days with NXT wash and receieved no QD touchups. However, I noticed notably less water spots on the Optimum coated hood. Whereas, the trunk accumulated them much more.
At the end of the day, I found Optimum to be great for a lot of things. I like to use it after normal washes to add a nice uniform gloss to the vehicle as well as enhanced protection. It also does a nice job of staying clean and repelling dust (great for rims!). All in all, I ended up ordering a gallon. This should be good for a couple of years

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Any questions, feel free.