It may sound silly, but it's safe. Be aware of jewelry and clothing with metal buttons, rivets and zippers. It's easy to accidentally rub them up against the car and scratch the paint. Your neighbors, who already think you're car craaaazy, will just have to look the other way.
This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2007/08/13/wax-in-the-nude