What would you do, no this isn't ABC!

You wash your car don't you. Vinyl tops don't care where the water comes from, water is water be it from a hose or from the sky.

Once cleaned/wax no I don't wash any of my cars. I use a detail spray.

Vinyl top rust is from years of driving in the rain hence the water under the top, there are ways to lay down sealant so the leading edge doesn't get the spray.