Ruffian,
A few answers:
1. It worked on my P-128 in a 2003 OB Special Audio Edition, which has the same set-up as the Limited.
2. Yes, me.
3. Almost no difference--I had to drill out one of the existing cooling air slots in the heat sink at the back* for the aux cable to pass out of the enclosure, and I drilled a hole in the back of the plastic single-DIN 'pocket' dash insert to bring the aux cable into the cabin, but that's about it.
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I'm VERY happy with the result. The ONLY drawback is the need for the silent CD, which means your music is interrupted for 1-2 seconds every 74 minutes. (Whoop-de-do.) But the P-128 and the Aux-In mod are absolutely compatible.
I encourage you to go ahead with it if you feel like you're up to the work as described in the installation instructions. Took me a little longer than some others have described, but I'm a bit of a plodder.
Feel free to ask more questions or PM me if you want to get into detail.
*Be sure to do this with the heat sink off the unit, and clean off any metal filings THOROUGHLY before you put it back on...