Traveling on the hwy in my wife's X1 at about 75 mph, everything normal, then an explosion above my head - didn't see anything that could effect the explosion - scared the sh*t out of me while driving. When I pulled over, the remaining glass was tending outward like something wanted to get out - glass everywhere. Removed the remaining 25% of loose glass and limped into Wichita Falls TX to find a vacuum cleaner to remove the glass pieces, followed by a slow trip home to Houston. My wife is not happy to see her car in this state......