This is a new aftermarket alternator bracket from VW that bolts to the top of the engine block. These brackets are prone to breaking as they are small and support a lot of weight, and are subject to a lot of vibration and stress. It is important to have the alternator secure to reduce the risk of the belt getting loose or flying off. Please note, original ones had a square hole for the bolt head to lock in - these have just a round hole so will require different bolt and holding a wrench on the bolt head when tightening.

Shown above as an assembly with the big bracket on the inside, the stock bracket (gold) in the middle and the alternator bracket fix on the outside. If you need, here are the BIG Alternaor Support Bracket and the alternator bracket fix.

If you use the alternator bracket fix shown above you will be able to use the stock alternator carriage bolt.

Ref ID: 025903141C