[ctuna]

https://www.ebay.com/itm/Bluetooth-A...NYyQ-s&vxp=mtr

There are a lot of options for aftermarket amp and speakers with the Hi Fi
system . But plan on spending between 1 to 2k if you want something nice.

BMW stereo types
http://www.e90post.com/forums/showthread.php?t=352586
http://www.e90post.com/forums/attach...2&d=1266451970
http://www.e90post.com/forums/attach...2&d=1260829447
http://www.e90post.com/forums/showthread.php?t=343673
http://www.e90post.com/forums/showthread.php?t=138949
http://www.e90post.com/forums/attach...1&d=1209780605
http://www.e90post.com/forums/attach...1&d=1209780865
http://www.e90post.com/forums/showthread.php?t=641323
http://bmwcoders.com/forum/3-er-8/bm...1-e92-e93-291/
http://technicpnp.com/menuDiagrams/d...e90_92_93.html

For sound quality improvements the stock amp is the weakest point the stock
speakers aren't far behind.

Bimmertech Helix 82dsp(or better) and a Speaker kit that replaces all the front locations is recamended. You might also call up Unexpected Creations and ask for package.

http://www.musicarnw.com/page-2/
http://www.e90post.com/forums/attach...3&d=1169133185
http://www.e90post.com/forums/attach...4&d=1278871872

examples

HI Fi upgrades
http://www.e90post.com/forums/showth...ighlight=level
http://www.m3post.com/forums/showthread.php?t=540446
http://www.e90post.com/forums/showth...hlight=technic
http://www.e90post.com/forums/showthread.php?t=532585
http://www.e90post.com/forums/showthread.php?t=833581
http://www.m3post.com/forums/showthread.php?t=443043
http://www.e90post.com/forums/showthread.php?t=324214
http://www.e90post.com/forums/showth...hlight=level+3

head unit
http://www.e90post.com/forums/showth...ight=head+unit
http://www.e90post.com/forums/showthread.php?t=1457320
http://www.e90post.com/forums/showthread.php?t=1036190
http://www.e90post.com/forums/showth...hlight=dynavin
http://www.janus-design.net/english/
http://www.e90post.com/forums/showthread.php?t=355089
http://www.e90post.com/forums/showth...ight=head+unit
http://www.e90post.com/forums/showth...hlight=dynavin
http://www.e90post.com/forums/showth...hlight=dynavin
http://www.e90post.com/forums/showth...light=retrofit
http://www.e90post.com/forums/showthread.php?t=993447
http://www.e90post.com/forums/showthread.php?t=1016187
https://www.bmwgm5.com/Logic7_E90_91_92_93.htm
http://www.e90post.com/forums/showth...hlight=dynavin