Now that I've got your attention, here's my question. I recently reinstalled the windshield in my '64 Mercury Comet without using any kind of sealant (these windshields mount using a gasket like an early Mustang or Falcon.) Now I'm wondering if I should have used something to prevent leaks. I've asked around quite a bit and I always get different answers on what to use. Some people say 3M Window Weld, some say don't use anything, some say electrician's putty, etc. etc. Even the glass places I called don't know. I have been told that there is some kind of mystery sealant that comes in a tube and is non hardening (flow grade butyl rubber?) that would do the job. I would like to be able to remove and reinstall the windshield again if I need to without destroying the gasket or paint on the car. So does anyone know what the name and brand of this fabled substance is?