[ShagginJet]

Here is the deal. Upgrading your front and rear speakers will give you a crisper mid and high sounds. You can run these off of your unit that's in the dash, regardless of it being stock of not. If you want to hear any true kick you're going to need a sub, it's going to go in the trunk, and you'll need and amp too. Bass is an omni directional sound, that means that even though it's in the trunk, you'll be able to hear it find. This will trip you out: If you do get a sub, have the box sit against the rear seat with the sub facing the trunk opening. This will allow the bass wave to travel back, hit the trunk, then bounce forward. What this does is makes the wave length longer which give you a richer deeper bass.

If you're looking for a heavy bass component speaker for your front and rear speakers, i suggest pioneer, they're pretty boomy. When you install them, make sure to put in a 200hrtz high pass filter in line with the + possitive wirre. This will cut out the low signals that cause distortion, it'll allow the speaker to concentrate more on what it's designed for.... don't worry, they'll still be boomy. You're going to need a 5-1/4" or above, anything below a 5-1/4 won't really have base, even the 5-1/4 itself is pretty weak.