I have bit of an old school setup in an '99 Miata. It is a simple install right now.
Ecipse 8052 HU
MB Quart PCE 216 components in stock locations.
Sound stream 2.370 100x2 Amp - (China made, not the original).
I've been turning it off and on to get it to my best liking, but wonder what it could sound like if I bi-amplified them, added a couple speakers in the rear, another set of 6.5" in the rear.
The Miata doesn't have any other speaker (stock) speaker locations other than the front stage - but I can cut into the rear deck on the left and right side to fit an 6.5 to even an 8" speaker on both sides behind the seats.
I have never had a sub but it seems these speakers want one some how. Some rear fill would be nice.