02/08/2014 I installed an Alpine UTE-42BT Digital Media Receiver and a Sound Ordnance b8td under the seat subwoofer. Here are links to the products.
Alpine UTE-42BT Digital media receiver at Crutchfield.com
Sound Ordnance B-8PTD 125-watt compact powered subwoofer at Crutchfield.com
I bought the Alpine off a forum member who also gave me the PAC unit for the steering wheel controls. I didn't wire that in just yet because I don't want to hack into the OEM wire harness. There is another wire harness out there with the extra wires for the Metra so I may end up doing that. This is just something until I get a nice NAV unit.
The head unit made a huge difference in the sound of the stock speakers! If you guys want something reasonably priced and want a great improvement over stock you can't go wrong.
As far as the under the seat sub goes, I have never had one before and didn't know what to expect. I didn't want to fork over the money for an audio integration box, sub, and amp just yet so I went with the S/O powered sub. It comes with a free wiring kit so that is an added bonus.
The install was a lot easier than I thought it would be. With the wiring kit is the black flex loom to cover the power wire so you can't even tell I have a wire running into the car. I used the grommet by the passenger side. It just came right out in foot well. Then I ran all the wires under the carpet by the center console. I then cut a small slit in the carpet to run the wires under the seat. The easiest way to do it is just unbolt the passenger seat and lean it forward so you can put the sub in. Then lean it back so you can have access to everything. You can't lean it back and put the sub in because the wire for the air bag blocks it. But with the sub in you won't have to worry about it.
For all the great reviews I am not the most impressed. I wasn't expecting to shake the rear view, but I wanted something that would be noticeable. Some songs it really lacks. It is supposed to hit down to 40hz but it can't really hit the lows. The wireless remote control is pretty much good for either turning it full blast or off. Don't really notice any in between. I was able to use the Alpine Subwoofer adjustments add a little more fine tuning. I called Crutchfield and they said that I could try the Kicker Hideaway sub and keep the free install kit if I wanted to. They have a 60 day no hassle return or exchange policy so that is great. I will give this a week or so and if I really am not happy I will see about trying the Kicker out. The only bad thing is that the kicker would still be another 140.00 since it is 300.00.
Kicker 11HS8 Hideaway? compact powered subwoofer: 150 watts and an 8" sub at Crutchfield.com
Here are a few pics. If I switch out the S/O I will take some pics with the seat leaned back so you guys can see how the wires come in. I tried to take some pics under the seat but they aren't the best.
If you look closely at the red cover on the battery you can see the wire coming off.
Here is where it comes into the grommet on the passenger side.
With the seat all the way back.
With the seat all the way forward.
Looking at it from the front underneath.