Great way to start the new year!

[ainarssems]

Sorry to hear. These bolts are supposed to be use once only so you need to replace them every time you undo them. I have seen them come loose on many VAG cars if not replaced. They are either different tread angle for bolt and nut(60&55 degree) or pre-coated with thread-lock so that they do not come loose easily. In my personal experience I never replaced them but always used thread-lock to prevent them coming out and never had any issues.