I decided to go a step further and connect the wire from the Bose radio plug that picks up the speed signal for the speed sensitive volume feature. Through research I discovered that the instrument cluster is the same part# on base 4 cyl. and Bose 4cyl models. The problem though was that my wire harness plug on the back of the speedometer did not have a wire at Pin # 31 (Should be a Violet/White wire on Bose cars which sends an '8 pulse signal' from the speedometer to the Bose radio head at speeds above 25MPH.) Now I was wondering how I was going to get a wire to stick in this connector and actually make a good connection. I could have called a salvage yard again but oddly enough a seller on EBAY actually had a used plug for sale, but out of a non Bose car. Well Bose or not did not really matter as I just needed any old pin with wire out of another instrument cluster plug. So when I received the plug I cut it open and took one of the pin's with wire out and placed it in cavity pin 31 on my harness, then I ran this wire to the Violet/White wire on the back of the radio. It worked! Another interesting note I will add here. In the past the first owner of my car had installed a Pioneer CD with Navi and he had connected to pin #30 on my harness (base and Bose cars use pin 30 as a command for power steering that is a '2 pulse above 12MPH). Evidently aftermarket radios use pin 30 for the speed signal. I guess I could have tried that but I am not sure how that would have effected or damaged the radio. The photo below is of the wire I added to my plug. The wire I used was blue with a red stripe.

Here is shot of he used connector with wiring that I purchased and later cut open to use one pin for the speed signal. The price was 25.00.

Here is the final install dash shot. A little water based black silicone helped blend the transition line from the cut I made where the radio face plate meets the climate face plate. All Bose cars at factory have dual zone climate control (different knob cutout) so you either have to use use your base radio plate (for a quicker install but won't have Bose and other nomenclature wording) or you cut the bottom of the radio face plate on both the Bose radio and your base radio. Then you install the Bose radio with the lower section of your base climate control cutouts. If you want to just use your base radio faceplate you can but you just have to remember to swap the green circuit board (as stated above) from the Bose radio face plate over to the base radio face plate. As mentioned above you can also remove the mute button and swap it out with the load button which is in that location on the Bose face. Also keep in mind that the radio bezel is NOT available separately (well it is on Navi cars but that's a totally different cutout altogether. So if you make a mistake cutting the face you will have to purchase another radio (can be a non working junk cheap one as you only need the face off it). Actually I found that there are plenty of base and Bose radios on Ebay and in salvage yards. Well, I hope this helped anyone who is considering the Bose upgrade.

I forgot to take pictures of the two tweeter replacements but they dropped right in. The plugs are the same so I cut the plug off of my factory harness and connected it to the wires I ran from the amp to each tweeter. As stated before, I did not install the 3rd center dash tweeter as I did not want to cut into the dash and I don't know what if any obstructions I would have encountered. (I left the center tweeter output wires going nowhere and tapped up at the back of the amp) In the wiring diagram, I noticed that the base radio wiring has the left front door speaker and l/f dash tweeter connected together on the same output. Ditto for the right dash tweeter and door speaker. On Bose models, every output from the amp is separate, none of the outputs are shared. That being said, the only factory wiring I reused was the front door outputs. The amp out wires for the door speakers I ran to the back of the radio and hooked them up to what was the base output wires to the doors on my factory harness plug. This way I would not have to run separate output wires through the door jamb loom (although you have to run those on the rear doors since base models have no rear door speakers or rear door speaker output wires). Again this is why I did not tie into the base tweeter output wires (I ran separate tweeter outputs) because they are shared with the base front door speaker outputs.

Actually, I find that the installed Bose system in my 09 Altima to have more base and somewhat richer sound than my factory installed Bose in my 08 Maxima SL. I listened to the sound at each speaker and found that the 'muffled base' sound on the Maxima just comes from the rear woofers. All the other speakers seem to carry the mids and highs. On the Altima, I find that the front door speakers AND the rear woofers are putting out the base sounds. That is actually interesting since the rear door speakers are the same part number as the front door speakers. This would indicate that the amp itself is what is directing base to the front door speakers as well as the rear woofers. Not sure if a factory installed 07-08-09 Altima Bose owner could chime in here and say if that is the same on their car but that's how it is after the install on mine.