As a music lover, I've never understood putting a crappy or amazing sound system in a car. 
 
		 
Well, I can see where you're coming from.  I'll speak for myself, then.  I commute to work (downtown Toronto) 5-6 days a week, every week.   Coming from the West End (suburbs), it can be quite some time spent.  Not to mention any road-trips and personal driving, that's a lot of time spent in my car.  Having a nice sound system to really enjoy my music means a lot to me.  A vehicle's cabin can be an outstanding amphitheatre to enjoy sonic bliss.  So, for me, having a nice sound system (I didn't spend 
too much, mind you, but enough) is definitely worth it.  I'll never own a vehicle with stock-sound again.