Did a stock speaker upgrade in my Sport with the Sony Premium Sound System.  Simply upgraded speakers, using stock amp.  Not the best “write-up” as it’s mostly pix, but hopefully it will be a decent jumping off point for those interested in doing more.  I just wanted a slightly better system as all my focus is on the performance (I’m not an audiophile, so my interest in this area is minimal).  I left the stock center dash speaker alone, didn’t feel like taking apart the dash, lol.  Hope the pix help folks out:

Subwoofer is a Kicker CompRT 8″ 2ohm DVC:

Added some subwoofer box stuffing since I had some laying around and it usually helps some:

Rear hatch area “D” pillar, I changed to some Kicker 3.5″ KSC350, ohm value is different as I could not find the speaker size with that ohm value (IIRC it is 6ohm), so it’s effecting the output, but it’s negligible:

Because I didn’t want the full frequencies getting pushed to these speakers, I matched the capacitor as close as I could off the OEM speakers and mimicked them to the Kickers:

Rear Doors, installed some Kicker KSC650 6.5″ coaxial speakers:

I got the rear speaker adapters from Metra, and the 1/4″ foam stripping from Amazon:

Unfortunately, the adapters that came from Crutchfield weren’t deep enough.  I had to order some custom MDF adapters from Sound Mechanix to be used in conjunction with the Crutchfield ones to give the necessary depth.  Size ordered was 7.5″ ID and 11.5″ OD in 1″ thick MDF:

And the speaker harness adapters also from Metra:

For the front door I didn’t get any photos of the tweeter install (I was getting impatient and wanted to just get it done, LOL).  But it’s pretty straight forward, it doesn’t come out easy and there is some permanent removal you will be doing but, it is what it is.  I made sure to wire it exactly the way it is from the factory and uses the passive crossover that came with the new tweeter.  Yes, the ohm value did change so it’s likely putting some small additional strain on the factory amp, but it isn’t driving low frequencies like a sub.  Tweeters were a pair of Kicker KST25 1″ and the 6x9s were some Kicker KSC6930 3-way coaxial speakers:

Front speaker adapters also from Metra:

And some wiring diagrams for everybody if needed!  Hopefully they are a decent resolution.