Nice testing you have going on.
I would use a car soap that leaves nothing behind like Carpro Reset or Gyeon Bathe or Gtechnic G-Wash. And if you use a prewash foam makes sure it don't leaves anything behind. IIRC the Honeydew Snow Foam leaves some glossenhancers behind. Also I would not use a drying aid either and if you must. Use something like McKees 37 N-914 rinseless wash in QD dilution.
I would wash the car weekly or every other week. To see how easy it is to wash and also after the test take a clay bar and clay it. To see if there is a difference between them as how much of bonded contaminants they get when you have called it done.
Very interesting to hear your experience with Hydro Blue that gets a longer longevity on the glass. I think I have got an explainationway it's so. It's the glass it self that has more of OH molecules so the SiO2 just bonds more thoroughly and harder to glass vs paint. Would have been awesome if these spray on rinse off products also did stand up to the wipers abrasions LOL. You can not get everything. But it's very impresive on the glass without any wipers on them. The HCW I think would be awesome for this since it's able to be wiped off and no need to be rinsed initially. Thinking about the overspray you would get if only wanted to be useing it on the windows.
You should make it's own thread about your testing. They are fun to follow and easier to find if haveing it's own thread.
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As far as TWSS, come on in, the waters fine, LOL. Atleast grab a bottle and put it on the shelf, Advance Auto Parts always has an online coupon code, so you can order it and pick it up in store
That said, I've used the CG's foam gun and it pre-washes with a soapy mix compared to the thicker foam the IK Foam 9 produces. 
