TTS 8J subtle tuning

[purenrg]

I have a 2011 tts roadster and would like more power from the two litre engine. I have looked at various parts and do not want to put on an intake kit or exhaust system as I like the sound of the standard setup.
Does anyone have any experience of remaps or plug in devices. I contacted Celtic tuning and they say I could get 315bhp from a remap and racechip say they can do more with a plug in.
All comments appreciated.