I have a CD/tape unit from a Matrix in my Vibe, both are 2003. In 2005 Toyota went with their own head units, so the connections/look are different. I would think that a CD/tape from a 2003 or 2004 matrix would fit a 2006 Vibe no propblem. If would not support XM or OnStar, as has been said.Today there are two Matrix CD/tape units on ebay.The first one,
http://cgi.ebay.com/ebaymotors...ZWDVW is wrong, too new and won't just plug in, and may possibly not have the red look you want. looking at the picture I am not sure that one is really a tape deck, althogh the listing claims it is.The second one,
http://cgi.ebay.com/ebaymotors...ZWDVW is what you want, one that looks exactly like the stock 1CD Vibe head unit, except it also has a slot for a cassette.On my Vibe, it was just unscrew, unplug the old radio, plug and screw in the new one, no wiring changes at all. I have also done this in a 2005 Vibe, no problems. 2006? I would think that it should be the sameI won't say if the price on that second ebay unit is good or not, I've seen them go for more or less than that one, but I suppose that since Toyota isn't putting them in Matrixes anymore, the supply is probably limited. They do come up from time to time though.