i did managed to stop by his shop to hear the demo and i learned alot.  So basically the DSP with amp is good stuff but he doesn't recommend me to get it first. What he suggested is that to keep my stock systems, change the components and add an sub below my seat. This is Stage 1.  He said once i would like to get a better upgrade that would be Stage 2 i.e.  it will be the speakers and tweets and finally Stage 3, adding in the DSP.

Whats your opinion on this?