Thanks for your help on this chaps, greatly appreciated as it was slightly niggling me.
If the harnesses were horizontal then the seat wouldn't be an issue.
As LWR states, a decent seat manufacturer ought to be turning out a solid seat but the seats in the RS Focus are Sparco and you can see what happened there.
It's a good idea to email Recaro though I'm almost certain they won't respond but lets see.
Thanks again