Thanks, I'll take a look at it.Welcome to the forum!
The 2.5L inline 5 rs3? That will be tough. 5 cylinders have a very distinctive sound. I agree, they said great but it'll be tough to do. Especially since it also have 50% more displacement than us...
Also, IMO, the rs3 has pretty aggressive sounding exhaust.
What I have done and feel like is perfect for me is only replacing the midpipe. It's cheap and eliminates the 2nd cat. So there's a little power gain and I feel like it sounds much more aggressive.
You can find a bunch of videos and stuff here - https://www.forteturbo.org/forum/19-kia-forte-turbo-performance/238-official-exhaust-thread.html
From what I've found, when you modifiy our exhaust it starts to sound like a little turbo diesel. That's not necessarily a bad thing. Pretty distinctive but maybe a bit surprising.