The Infinity BassLink has an all- around look and feel of quality and will delight you at every turn. The designers of the BassLink obviously worked overtime to get it right. For an application as a self-powered subwoofer intended to be mounted in the trunk, the servo-control is indispensable ? it compensates for changes in the enclosure (i.e. your trunk) as the shape and volume of the enclosure changes (i.e. as you put things in or take them out of your trunk). Read on & you?ll see why the BassLink is probably the optimal upgrade for to compensate for a weak low-end (but otherwise fine) auto audio amplifier. I put my BassLink in the trunk of my BMW. The stock audio system found on all BMWs are severely wanting in the low end, and we all tend to overdrive the amplifier to (try to) get more bass response. This doesn?t work well in practice as (1) we never do get balanced bass response, and (2) we drive the amp to the point of distortion in the midrange and highs. The BMW amps (both standard and Premium/DSP) are *really good* in the midrange and highs; it is just the lows that is too wimpy. The BassLink fixes this, and fixes it ?but good!? There are several kits around to help with installation. For BMW, I recommend the BassLink Install kits you can find on eBay (just go to ebay.com and use the keyword search for ?BassLink Install?). The kits will save you a lot of time and they have all the components you need ? there is even one that has a ?QuickRelease? mechanical mount so you can take the BassLink out (and replace it) in under 60 seconds. The kit is highly recommended as (1) it has all the information you need (2) it will save you a lot of time, and (3) it has the hardware ? including the ?QuickRelease? mount. There is a good article on Basslink for BMW at: http://www.wakajawaka.org/bmw-audio- upgrade/