Stereo Upgrade x 2 (Prius & Prius V)

In the past three months, my wife & I have become the proud new owners of a 2012 Prius Two & 2012 Prius V Two. I have really appreciated all of the information available on this site, and it was a great help with making the final decision to buy both vehicles.

So at least to our ears, the factory stereo system included with the Prius sounds pretty rough. We've decided to upgrade both systems with a goal of getting the best overall sound quality and bass response possible, but without replacing either the factory head unit or adding a subwoofer. Our budget is also limited, ideally less than $500 per car. I have installed numerous aftermarket systems in the past, so should be able to save some money by handling the install myself (I hope!). After a ton of reading (most of it on this site), here is what I'm planning...

• Replace the front door speakers with a pair of MB Quart PVL269 6x9 components (MB Quart PVL 269 (PVL269) 6" x 9" 2-Way Premium Component Speaker), surface mounting the tweeters on the A-pillars. The thought here is that the 6x9 components would be the best way to maximize bass response without a sub. One concern I have is that the 88 dB speaker sensitivity will result in an overall front speaker volume that remains neutral or is slightly lower (assuming factory head unit puts out +/-12 watts to presumably efficient 90+ dB factory speakers, and a +/-6 dB volume gain using the amp below).
• Replace the rear door speakers with a decent pair of moderately priced 2-way speakers, 6 1/2" for Prius & 5 1/4" for Prius V. Not sure yet of the brand but maybe something at the Infinity/Polk level of quality.
• Disconnect the front factory squawker speakers.
• Add an Alpine KTP-445U Power Pack 45x4 watts RMS (90x4 peak) amplifier (Alpine KTP-445U "Power Pack" Upgrade any car radio to 45 watts RMS X 4 at Crutchfield.com). While it's not the beefiest amp it does seem to be small, efficient & has received some very positive reviews. Plan is to power the front and rear replacement speakers with the amp. Based on power ratings, it seems like it would a nice amp to pair with the MB Quart 6x9 components.

For those of you who have upgraded your system, I wanted to get your take on this setup. I also have a few questions about the upgrade. Specifically...

• From my reading here, it seems that 6x9's with a mounting depth of +/- 3" can be installed in the front doors. To make that work, is it a matter of just reusing the factory speaker mounts (and trimming as necessary)?
• What seems to be the best place to mount crossovers for front components?
• Can the rear factory speaker mounts be reused as well to add additional mounting depth?
• For those who have removed the factory head unit, is there adequate space to tuck the Alpine Power Pack in the dash behind the head unit? The unit is 8"w x 1.5"h x 3"d.
• The Alpine instructions suggest using the factory head unit power lead for power. Will the Prius head unit circuit support up to an additional 15 amps (based on Alpine fuse size)? I looked at the Prius manual and found three fuses that looked like they could be related...[1] #9 "AMP NO. 1", 30A, "Audio system"; [2] #26 "AMP NO. 2, 30A, "Audio system, navigation system" & [3] #33 "RAD NO. 1", 15A, "Audio system, navigation system". Wasn't sure which one actually powered the radio - if it's #33 then I'm guessing the Alpine would need it's own lead from the battery.
• Is there any value to installing new front squawkers with this setup, moving the rear speakers back to head unit power, & then running the front components and squawkers off the Alpine (assuming I can find 3 1/2" speakers that handle that type of wattage)? My gut feeling is that the A-pillar tweeters would be enough, but thought it was worth asking.

Thanks to everyone in advance for their input. Wanted to make sure that I had a decent plan of attack, as I'm going to need to install and live with this system in two vehicles.

 

Good suggestion...will add Dynamat, FatMat or the equivalent to the mix for all doors. I've seen a couple of posts about sealing the holes in the interior door sheet metal before soundproofing. What the consensus on that process? Worth the effort?

Regardless of soundproofing, the speakers have got to go. No matter what settings are used, they sound horrible. There doesn't seem to be a lot of information available about using 6x9 components in the Prius, so I may just take a chance and try the MB Quart PVL 269's and the Alpine Power Pack.

Also, has anyone reused the factory speaker wiring with an amp?