I believe the poster is asking about the bass system.
I have seen a few posts from people who liked this system ok. It depends on what you want. Which car do you have? What are you looking for as far as sound? The ad says "smooth deep bass" but I am not sure how "deep" a 6.5 inch speaker will go. Frequency range is related to speaker diameter. Larger diameter speakers tend to better reproduce lower freqs. I have heard very nice 8 inch subs that sounded good but those come from aftermarket suppliers. Give us a little more info on what your goals are and what you currently have.
I was thinking of the same thing. I don't want to pump a ton of money in, just get sound about as good as some of the Bose setups I've heard, like in the Mazda3. My EX sedan has really uninspiring sound now, but I've got the navi and I really don't want to have to get much of a non-OEM look.
Not worth it unless you're really really anal about installing aftermarket stuff.
I looked into it and i think it ran over $300? Don't quote me - it was a while ago.
I'm assuming you're looking for subwoofer type bass. Get an aftermarket sub and amp. A reputable 8" and an amp pushing at least 120 watts in a sealed or vented box should be good enough.
Remember, these speakers you're looking at probably won't play subwoofer frequencies well. They're not subwoofers!