The 50/50 panel, not a bad idea really. But I'd have as much print material and as many photos displayed as I possibly could. The idea of "everybody wins" is pure genius! My wife has done that with Mary Kay forever (first heard about something like that when I was a kid).
Signs and banners of product are a plus, people see a brand they've seen before and it makes them comfortable. Remember the first time you smelled ONR?

Products on hand help them understand what they are getting. You can bet that 99 of 100 have NEVER seen a big thick MF towel. Might want to have some handy (even if they are just hanging where they can feel them). What's the saying... "Baffle them with brilliance and befuddle them with BullShi#"
Still like the 'before and after' stuff just to show what is possible. Sometimes photos are not the best way to display the difference either. Only you can decide what would look right, and what looks like a con artist.
Might be fun to have a panel there to let the public 'practice' on to see what they can do with it. Then you take over and whip it into shape right before their eyes.

Just don't want to be like the new car show guys and put flames on the paint to show how tough your new 'miracle finish' is. Just gauge their interest by if they are willing to try and work on it themselves. Heck for that matter put two side by side and get them to race each other. :dunno: Sounds like fun.
Bottom line is you recognize that there is a market in your area and you are ready to capitalize on that market. I've been thinking some of the same things here. There just isn't anyone locally, other than the 'tunnel of doom' car washes. To be honest, I bet that'd be a GREAT place to get work. Park outside the car wash and tell everyone that drives out how bad their car looks!!! :laughing: