Just my 2 cents, if anyone thinking about upgrading a top hifi sound system in their E70 X5, don't do it. The components are not inferior. If you look inside a top hifi amplifier you will see discrete circuitry with Rubicon Blackgate caps. The amps are made by Lear Corporation. The speakers are carbon fiber and have small but powerful neodymium magnets, Siemens Polypropylene caps for the tweets, The Subs are made by ETON. If the sound is not good it is because the inside plastic panels need rubberized sound deadening. Do that and you will save yourself from destroying your car. Somehow Bavauto generaly says how cheap the BMW speakers are, mine are 8 years old and never had issues. The only issues I had were rattling panels when I cranked it up, that is all history now. Their is also a provision on top high fi amplifiers where you can add a cooling fan which can be had for 5 dollars at newegg.com. I will say, before 2006 BMW audio sucked. Base audio model need alot of help. Just my 2 cents.