The clips are cack, yes!
There was 2 lambda holes in the system I fitted,
The rear lambda was awkward but has now been sorted with a 90deg lambda adaptor.
It can rattle if its not fitted properly, usually with the crappy clips that are supplied.
Needs to be adjusted so it doesn't knock on the rear beam.
This exhaust is very good quality and does get quieter with time.
If your mates exhaust is blowing, it hasn't been fitted properly.