I took my A6 to a Hunter alignment garage yesterday and there's a possible issue with the left rear camber. Before adjustment it was reading as -1 deg 18' and after it is reading -1 deg 16' (the right rear for comparison is -1 deg 5'). This is outside the recommended range for it but they said it wasn't by much. The issue is they have reached the limit of adjustment for it and said they would probably need to weld something on to give them more adjustment on the (bolt?).

While I understand what he's talking about in general, I'm hoping someone here may be sufficiently knowledgeable and/or have specific experience of this to be able to recommend the right solution for the job?