Thanks, the logo is my name.
The most important thing with any coating is the paint prep before. Can use a simple claybar/mit before a spray coating for better results.
I use turtle wax polish n ceramic as a one-step correction to keep costs down.
Of course, you can do a 2-3 step correction plus coating if the customer wants to pay for it.
The cheap and time-tested compounds that I recommend are sold out everywhere, but you can try this one https://www.amazon.com/Turtle-Wax-53412-Solutions-Ceramic/dp/B07XYPS3PV/ Best is to walk into nearby auto parts store, they'll have something, online shopping is not what it used to be =(
It's doable by low-nap microfiber towel, but much more convenient with 3-inch foam pads that are sold for drill attachments.