The subframe knock issue is common amongst the Golf and Jetta MKV and the Passat B6. If you have taken your vehicle to the dealership but they have not been able to solve the problem, here is your solution.
These bolts and spacers replace the stock bolts that connect your subframe. Over time, the stock bolts stretch and allow slop in the front subframe. Replacing your stock units with identical replacements will only delay the issue and it will reappear after the replacements stretch. Use these replacement bolts to tighten everything in the front end back up.