I have heard that they are ok, my friend used to have them in his civic, but personally I would stay away from them because their amps are crap, but they subs are nice if you are into the German thing or the red thing. They do hit hard but I would not recommend them to anyone. Not sure of the quality or life of the sub. I have learned from my mistakes in the past so I just stick with the quality that I know of the kickers. On top of that there is a formula somewhere posted on here that can tell you how to figure what kind of RMS it will put out but if I have been researching correctly its around 200 Watts RMS per channel. Which total is 400 Watts all the time which in turn is not so good for what you are paying for it. I would do a little more research before jumping into the volfenhag seen. You can go to like sounddomain.com and read some reviews and such to make your decision, thats what I do and I have yet to be dissapointed.
For some odd reason I think that the Volfenhag woofers and amps are cheap for a reason. Just wouldn't get them, but hey its up to you buddy.
Hope all this helps man, sorry if I sound critical just like to do my research first before I make any kind of decision.