Rear Speakers

kenchan

for me, i found that running full range drivers in the rear in a small cabin like our Z's emphasizes too much high's and make the sound too tinny.

as for running an amp for the fronts, yes, it can sound significantly better depending on how loud you want to play and wat drivers you plan to run. for most folks, using the HU's internal amp is plenty imho.

Fountainhead

yeah those rear drivers aren't much bigger than the tweeter/mids in the dash.
If I had it apart I'd try bandpassing them to make the best use of their frequency response without stepping on the tweeter/mids in the dash but as BAF said they're only filler, not providing the soundstage so to speak. I think they're an after thought for number of speakers bragging rights at point of sale.