That was because it was a store 'demo' and they couldn't find it. However, here's what happened next: I installed it in July 2002, real easy without the manual. In September, it went dead! So, I searched around the net and managed to find a copy of the service manual (not owner's) in English on a Russian website for $10.00, which I downloaded and have. This was a big help to the shop that fixed it under warranty from Kenwood (but doesn't contain any instructions, just schematics and part numbers). It's been back in action since April this year and still works fine. I also found a copy of the owner's manual, but in Russian. From the pictures, and a little help from Altavista, I decided I didn't need the owner's guide anyway. (I'll try and find the site where I got this and post it if I find it again).
Basically, you have a choice of input: a low-level pre-out from your head unit, via RCA cables, or tap into the rear speaker leads. Doesn't really matter which, so I just connected the marked speaker leads on the WooX (4) to the wires going to the right and left rear speakers (easy to do, just go up under the package shelf). Next, connect the marked lead to the wire that triggers your antenna to go up. This is what turns it on when the head unit comes on. Lastly, there is a power wire (12V when IGN is on) and a ground. That's it!

__________________
1986 560SL
2002 Toyota Camry
1993 Lexus