big time question on air intakes for a6's

see what all u think of my 99 audi a6, 2.8 awd, i want to get a AIR INTAKE system to boost the HP on my car but i have 2 worries. 1 is that i dont want it to make loud noise like a rice rocket i dont mind the sound of a nice engine but nothnig like a garbage big air muffler sound. 2ns question is i heard it is not good to put air intakes and other thinfgs on audi's specially a6's there not meant for it. if you guys can help ill appreciate it hope this site is helpful and looking foward 2 help others as well. o yeah if u have any request for specific intakes and prices it will cost me lemme no as well b/c i no K&N filters dont make anything for my car... here are some pics of my whip!!! lemme no wut you all tihnk on the link b/c i cant add pictures here the files r too large check it
http://www.cardomain.com/ride/827320