If you have an SVT, then you have it. at least i think so...
Basically, to describe it wouldn't take to long...I wouldn't call it junk, but it's close. Far from premium.
It is possible to cheaply upgrade what you have though. A simple HU swap seems to give the most bang for the buck.
You can also add a powered sub with similar improvements.
I think the agreed upon order of improvements would be
1. Head Unit (200.00 will get you pretty good sound)
2. Subwoofer/amp
3. Replace 4 door speakers
4. multi channel amp
5. EQs, seperate crossovers, better wires, capacitors, etc...