In the thread regarding suspension noise, one respondant suggested that the noise was caused by their camber control arm hitting the subframe. They showed a mark on the right hand side CCA which implied this.

As I was suffering a similar noise (later discovered to be a faulty shock absorber, waiting for news on a replacement), I looked under my car and found the same mark. It seemed unlikely that the design would allow this to happen... but it did make sense.

However, it appears that all RX8s have this mark; MX5s have it plus a yellow mark. I looked under the new ones in the showroom.

What's it for? I'd assumed a manufacturing mark to identify left and right sides?