I've had BAs in my car for almost 6 years..... I use the stock head unit (believe it or not, the Matsushita/Panasonic factory head units on Preludes are very good. Strong, clean tuner and the CD player is better at decoding all the hidden nuances than most home CD players), an 8 year old Pioneer amp for my rears, a 6 year old Alpine amp for the fronts, and Boston Accoustic speakers all around (factory sizes - no subs)

I've had people with high end home stereos tell me my car stereo sounds better