Some exhaust questions

[optionclick]

My apologies if this has been asked before - the search tool wasn't bringing up anything appropriate!

I have some general questions re the exhausts:

1) am I right in thinking that the exhaust setup is as follows:
turbos > downpipes (with precats) > cats > back box

2) is there any advantage of gutted RS4 downpipes over S4 ones? If so, is it a straight swap onto a standard S4 system?

[imolas4uk]

Rs4 downpipes have 200 cell main cats,s4 has 400,so get some rs4 pipes and gut the pre cats or get some catless downpipes if you can put up with the noise,s4downpipes are different lengths and rs are the same length,you will need link pipes to mate to a s4 system.
I have rs4 precat gutted downpipes and a 3 inch milltek single cat back,it's still quiet disspite being 440bhp