Vaseline (petroleum jelly) and Glad Wrap (Plastic Wrap) as car paint protection?

I don't see why it wouldn't work. Although the saran wrap might get ripped up if there are a lot of back roads you're going on with rocks getting kicked up by cars in front of you. The vaseline won't cause any problems, just will take a little bit of time to clean off. If you leave the saran wrap on the car for a long period of time, it may cause paint fading by keeping heat under the wrap and on the paint.