I put the firepower in my '01 and love it. I did have to use the adapter harness, even though their website said I didn't. Of course, plugging in the coil was the last thing I did, so when I discovered it wouldn't fit, I had to un-do everything so I could drive to work in the morning. When I called them about the plug, the guy on the phone said it would not work on an '01, so go ahead and send it all back for a full refund - even though everything had been installed. A week later I checked my card and the refund from them was $70.00 less than it should have been.
I called about the lack of full refund and was told it was because the wires were "used", so they were sending them back to me. When I explained the situation, the person i was speaking with was shocked that someone there said that it wouldn't work. To make up for their mistake, they not only sent everything back to me on their dime, but included the adapter wire at no charge. I guess it evened out with my costs sending it back to them.
I'd recommend ordering straight from their website. That way you can deal with them direct if there are any issues.