a Blow off, is atmospheric - it releases into the atmosphere creating the whoosh.
thats all good, but the tfsi is a fully recirculating system, so fitting any kind of BOV can / will lead to some kind of failure / issue etc.

e.g the forge spacer, which allows for a "woosh" noise, sounds good but effects performance. i had mine for about two weeks before taking it off and getting annoyed with the effect it had on the top range of the rpm and higher boost.

the diverter valve, is what they use for the fully recirculating system so is a closed system, making no woosh.

you have a neuspeed, you should have all the noise you could need, and yes a CAI makes a far better noise than a BOV. if its not enough, get a remap. increasing teh boost, will make the turbo create a better noise.

and as for location, open bonnet, just right of center, at teh front of the engine is where your dirverter will be.