Sub Advice

[BurningSky]

Hey all,
I bought my car about 2 months ago now and since buying it have had the Parrot MKi9200 system installed so I can use hands free on my iphone, use a laptop hard drive for music etc.

Since doing so though I've realised I need more bass...

I was wondering if anyone had any ingenious methods of increasing the bass without compromising boot space too much. Has anyone done anything like this or put speakers in the back bits (dunno the tech term :-P) next to the passengers? Also can anyone suggest some good, reasonably priced set ups?

I've looked into those small sub units but I don't really know much about car stereo equipment so don't know what's good and what isn't

I found these:
Alpine SWE-1000
http://www.caraudiodirect.co.uk/alpine-swe-1000.html

Focal Access BUS 20
http://www.caraudiodirect.co.uk/foca...ss-bus-20.html

Ground Zero GZUB 800ACT
http://www.caraudiodirect.co.uk/grou...ub-800act.html

Kenwood KSC-SW10
http://www.caraudiodirect.co.uk/kenwood-ksc-sw10.html

Pioneer TS-WX77A
http://www.caraudiodirect.co.uk/pioneer-ts-wx77a.html

Obviously cheaper is better but if anyone thinks one is better/worth the money then ill take that into consideration. Does anyone have any experience/thoughts about these or recommend any different/better set-ups?