Thanks, that was quite helpful. Just knowing what speakers the amp is driving helps. We know that the stock amp is not putting out 350W RMS, it is more likely the max rating. Also, note that the stock speakers ar 2 ohms. If you replace the speakers with aftermarket speakers you may want to try and find 2 ohm speakers. You can use 4 ohm speakers put they will be even more under-driven by the amp. My Infinity Kappa's are 2 ohm but I think I may try and find something that requires a little less power than the 90W they need.
I had never heard of CDTAudio before. Anyone have any input on them and their products (other than the reviews they post on their page)?