Best A1 1.2 exhaust ??

[skirs6]

My son has a 2014 A1 1.2 tfsi 89bhp. To get more sound he has removed front muffler plus rear box which was ok, but then went Supersprint down pipes and the noise was horrible just sounded like a broken exhaust. He then put the smallest possible power flow back box on but that has stopped too much sound. "I've no pops and bangs!!" etc.
Any ideas on best options without spending a fortune would be much appreciated. He's 18 and starting to piss me off with his constant moaning about how his exhaust sounds <beep>.!!!!!!!