Bought Appradio 2 - need to build out

[H2O_Doc]

BestBuy was clearing out their Appradio 2s, so I picked one up for $199. Seemed reasonable as I planned to add a backup camera and needed either a new HU or mirror. Since I also wanted BT, seemed like an ok choice (I DIDN'T want a nav HU - I like the smart phone offerings better).

My thoughts are to do components in the doors: I've had good luck with Rockford Fosgate and am considering T-1675s. If you feel strongly about the door/dash speakers, please advise. Note that I will add a subwoofer; that might logically affect comments.

I have the non Bose system (2012) and only have vacant grills in the back; is it worth putting something there?

I'm struggling with which way to go with the subwoofer. I have an extra polk 12" sitting around and was considering putting it into one of these:



Reasonable? Horrific overkill? Note that I like a broad spectrum of music from classical to what could be described as "contemporary urban ethnic sounds." Other ideas on a sub?

Is there a big variation in backup cameras? Should I go inexpensive or just get the pioneer?

I noticed there is a fair bit of road noise. although a certain amount is an enjoyable part of the whole zexperience, I have a roll of dynamat laying around and wouldn't mind putting it to good use. Is it worth the trouble to do some sound deadening? Where is it most or least helpful? Anything else anyone wants to offer is welcomed. I am a 2nd day member, but have already taken to going through the very informative write-ups.

Thanks to y'all.