In both my vehicles.. 
The amp'd component system in my MR2 is, in my opinion, utterly fantastic - but completely lacking solid low-end.
I just installed a Sony CDX-GT130 and Pioneer speakers in my sister's car - even with the speakers running off the head unit, it sounds fantastic. Sony isn't my favorite (I'm partial to Pioneer), but it was in her price range and we were stuck with buying local (Best Buy and Wal-Mart). I added some spare parts I had kicking around -- amazing what a little bass can do!

The amp'd component system in my MR2 is, in my opinion, utterly fantastic - but completely lacking solid low-end.
I just installed a Sony CDX-GT130 and Pioneer speakers in my sister's car - even with the speakers running off the head unit, it sounds fantastic. Sony isn't my favorite (I'm partial to Pioneer), but it was in her price range and we were stuck with buying local (Best Buy and Wal-Mart). I added some spare parts I had kicking around -- amazing what a little bass can do!
woot!