intonation

I have a loaner A3 S-Line and the sound system sounds great compared to my A4. I noticed it has a sub built into the trunk (in the left side compartment where by the sat radio module)Is it possible to add this to a non-Bose A4?

vtracer20

look at Infinity basslink.....heard great things about it and it's a sub/amp combo.

co_pa

heard in an a3 and looking to
install in my avant. tight and musical bass.