I installed a JL Audio 10" sub last night, and it's pretty sweet. I've never had a sub in any of my vehicles before. Actually, I've taken them out when I buy one that has them. But in my defense, I was always taking out big 2 12" boxes....and I just installed a single 10".
Anyway, the truck already had a little Alpine MRP-F250 amp running all the components. So I just switched some wiring around, bridged channels 3 and 4 to the sub and it was done. I got the amp dialed in today, and now I look forward to listening to my tunes in the truck because it sounds damn good! Plus by running my components in parallel (just using channels 1 and 2), I dropped the resistance to 2ohms, so I get a little more power from the little Alpine. Seems to be working very well so far.
And I received my Yakima wind deflector. Works perfect, no more howling. And I'm still getting 19 mpg, including a lot of in town driving. Easy does it on the throttle.