Hi guys, I am hoping a guru can help me out with some good car audio
advice. I have asked so many people in shops for advice and everyone I
speak to tries to sell me some new system that I don't need.

This is the story: I have a VW Golf VR6 with a great sound system but I
want to see what I need to do to get some base out of it. The guy I
bought the car from a few years ago was an audiophile and spent a bit
of money to have it optimised for the type of music he likes. This
happened to be music without much base. This is the setup:

- Nakamichi CD-35Z headunit
- Boston Acoustic ProSeries woofer and tweeter in front doors
- Boston Acoustic ProSeries woofer and tweeter in rear doors
- Boston Acoustic 'crossovers'
- Xtant 404m amplifier (4 channel)

This produces good results but it doesn't offer any decent base out of
this system. So this is what I'd like to know:
- What are my options, without having to change too much of my current system?
- What do I physically need to change/ad so the system can produce some base?
- What is a realistic budget? I am happy to spend some money, I just
don't want to get ripped off on something I don't actually need.

I don't know much about car audio and terminology, so please excuse my
ignorance. I'm learning, but that's why I'm asking you guys.

Any advice people can offer would be greatly appreciated.

Thanks,
Mon