Anyone ever heard of these/used them on a scooby? am mainly talking about downpipe.

 

I have tried the oval Superspint backbox. It is a *very* quiet backbox, just a bit noisier than OEM but of excellent quality (and quite heavy actually).
I would recommend it only if you require a very quiet backbox. Not my cup of tea. I now have a Magnex backbox.

 

Markus, I have a Supersprint downpipe & centre. What exactly would you like to know ?