Nanoskin as in the "clay" replacement? If you're going to use that with Glide or hydroshock, or whatever they recommend to use as a lubricant, you're going to want to either do IPA wipedown or use Eraser. It would suck to skimp out on a $21 product that will do multiple cars, and then have your CQ not bond to the paint because of the Nanoskin lube residue. I've used it before and I'm pretty sure it can be used as a drying aide because it has hydrophobic qualities.
I only used about 1/3rd of my 50ml CQUK kit, it's definitely enough to do 2 cars, depending what Lexus your finacee is driving. If it's something like an RX you might not have enough to do your WRX also.
WRB should be easy to see the product flash. All of my high spots were near the hood, where it meets the bumper, so that might be a problem area for you to concentrate on applying evenly, and buffing off entirely.
I'm planning a full detail of my car and have a few questions.
Try a paint degreaser, those look like greasy hands! https://www.amazon.com/Eraser-Intense-Oil-Polish-Cleanser/dp/B00FY0XY1S Isopropyl alcohol can work too, but will degloss more.