I learned that when the windscreen is replaced the tabs don't break but they don't hold very well when replaced I never had problems with mine untill i had to have the windscreen replaced it wasn't but 5 days later and same deal it blew off going about 75 with loud thump. I contacted dr glass and he found and replaced it with a new one at no charge to me. He said it's common on alot of cars Cadillacs in particular.