06 tc what would I need to do just to add a amp to the factory headunit

 

If you get an amp that has high-level inputs, all you'd need is a bit of speaker wire to splice into your rear speakers and go from there to the amp. Otherwise you can get an LOC (Line Output Converter) that converts hi to low level (speaker to RCA) so you can run RCAs to the amp's inputs. I did the latter and went with the Scosche SLC-4, which you can get for $20 from this site.

 

how does it sound? I just want some bass for now until i buy a nice amp for my door speakers. I bought the JL (Zr series?) components for the font.. there like 800 bucks on crutchfield I can't wait to hear them...

 

Sound going through the SLC-4 is great, seems just like using a head unit that has RCA outputs built-in. It'd be a great solution for your intended purpose.

 

i had the converter for a while and it sounded nice... but when i got my head unit it sounded 10x better

 

^ Not all converters are created equal, SLC-4 is one of the better models available.

I agree that a HU upgrade is preferred for SQ, but some peeps want to use the stock HU.