RE: Dual 10"
to start,u will have to buy a seperate amp and have a custom box built,because they dont make a factory right side box,then u will have to search and see if u can pick up a second kicker sub,which may or may not be easily available (if dodge has them specially built or if they are just an every day kicker sub)
heres my thoughts on this subject:
you would be better off taking the stock sub enclosure out,and replacing it with a custom box and add a matching right side box,and if possible order an exact replacement sub for the right side. then u can have matching boxes and subs,then u will need an after market amp capable of powering 2 subwoofers and u will more than likely need a hi-lo converter to tap into the stock sub wires for the sound to get to the amp (hi lo converters are only like $12.00)
take my word for what its worth to you..i think kicker is a good company,but if u were going to spend the money u could walk away with a JL audio sound system for around 130$ a sub woofer and about 300$ for an amp...more than likely an "oem" kicker sub from dodge will cost you a fraction of what u paid for the car. but i could be wrong.
JL audio in my opinion is a much better quality and you get what you pay for,and another plus is you can have a bass knob for about 30$ and install it somewhere near the captains chair so u never have to go into your settings to adjust your bass for those songs that just didnt sound right from the settings you had for the last song u just listened to.
hope this helps.
-marty