1. Where and how much?
You can probably find it cheaper elsewhere.
2. Is it easy to install? How? (Could be a how-to...)
I installed it along with the rest of the stereo equipment I added to my Intrepid, so I did not think to consider it as a seperate project.
Mounting it was no big deal, it fit right through the old antenna mast's hole and I just used that rubber base from the bottom of the old mast to get the mounting angle right.
Inside the trunk you need to add a metal brace (included in kit) to help support the motor.
I ran one control wire from the head unit to the motorized antenna which tells the antenna when to raise and lower.
I ran a second power wire from the powered sub in my trunk to the antenna to provide power to the motor.
I ran one ground wire from the antenna to one of the screws on the metal brace supporting the antenna motor.
The last thing I connected was the antenna lead from the head unit to the motorized antenna. This one was a little more work, because I could not find an adapter locally to simply hook the new lead into the existing lead in the trunk. The antenna lead from the stock radio in the car ends in a male plug which fits into the stock antenna mast. The antenna lead from the motorized antenna also ends in a male plug. This meant I either need to find an adapter with female plugs on both ends, or run a new antenna lead from the trunk to the head unit that had female at one end and male at the other. While I'm sure the adapters exist, I just did not care enough to run one down, so I cut off the two male adapters and spliced the antenna leads together using some parts I had on-hand. Everything seems to work, so must have done it correctly.
I was asked (a while back in this forum) whether the power antenna performed better than the stock antenna, but I could not say if it does or not. Since I replaced the head unit at the same time as the antenna, that would have made a huge difference in itself. I do know that I have much better recption over my stock stereo system. Kind of waste though, I hardly ever listen to the radio.
I'll get some posted tonight.
Man, I did not expect to run on and on like that. Maybe I'll get credit for 2 posts?