Well, I haven't tried this adapter, specifically. While
controlling an iPod through the stock stereo seems cool, I have another idea for you, since it sounds like you're not using an iPod. (I don't either, for what it's worth)
You can probably guess what I'm going to ask you next... Are you really that attached to your stock head unit? I replaced mine with a Clarion head unit that was about $150 a couple of years ago. The new stereo sounds much better, and it came with an auxiliary input (two RCA connectors on the back, but some have a stereo jack on the front). I've got a Y cable running out the back, and I plug in my MP3 player into that cable, routed through the center console box. It looks very neat and tidy, and I have 20 GB of music to play.
If you're interested, you can find the right features and see what fits your car at Crutchfield. (Though you may not want to buy it there. Crutchfield has awesome service, but you pay for it.)
Scosche makes wiring harness adapters and plastic inserts so the new stereo fits. I bought both of those on eBay for about $20-30, if I recall correctly, though Crutchfield will include them in the price, along with instructions for taking your dash apart. If you want to know what you're getting into, they also
sell the instructions for five bucks!
Good luck...
Jim