Since there is a 4130 chromemoly roll bar/shoulder harness attachment just aft of the door rebate that will not allow access to drill hole from rear for ball mount stud, much easier to mount on strut channel.
Few things worth mentioning, when drilling lug, aluminium chips came out, so there is an aluminium insert in the horn from factory. Also there is a ply of carbon fiber from the factory on our polyester resin doors, we added an extra ply of carbon fiber using Aeropoxy laminating resin and filled with Aeropoxy light. We sanded through gelcoat first. We needed to use the ball ends from our plastic strut ends because they were longer than the ones that came with the metal ends. Note that 5mm threads are very close to American, you could screw an American nut bout half way up stud. Make sure you use metric tap.
Y9-12-03
