Thanks Scambledsignals and Graham
My Plus 4 was one of the cars that had the problem with cracking along the joint between the wing and headlight cowl. It was the joint that cracked and not the aluminium.
From the photograph this looks more like either a fatigue crack or an impact crack. I think I would investigate if this is in the metal or is just the paint before I drilled any holes.
Have been distracted for a few days but I will rub down the paint and see what is going on.
David
