You could argue it's mostly common sense, and I assume it's applicable to other soft tops made of the same material.Gently clean the convertible top with a synthetic neutral detergent, lots of water, and a soft brush.
Automatic and high-pressure car washes are harmful to a convertible top. Avoid them.
Some leather treatment products can ruin the convertible top's gloss. Be careful of the one you choose. Test on an inconspicuous, small corner of the convertible top if you are not sure.
Do not wipe the convertible top using alcohol, chlorine bleach, or organic solvents such as thinner, benzene, or petrol. Otherwise, they may cause discolouration or stains.
Do not get any car wax on the convertible top. If you do, remove it with a good leather cleaner or mild detergent (about 5% solution).
The results you get from snow foam depend on what else is on your paintwork protecting it and how dirty the car was to begin with. Anything you can shift is a benefit because it won't get caught in your mitt at the contact wash stage. Avoid the temptation to bring the pressure washer closer to the paintwork to try and shift more dirt - you don't want to force water into places that it shouldn't be.