pontiac vibe 2007 sony cdxgt550ui stereo

New installer, trying to install a Sony CDXGT550UI MP3/WMA/AAC Player CD Receiver. I have got Metra wiring harness also (Metra 70-2003 Radio Wiring Harness For GM 98-Up Harness) Can I just connect the Sony harness and metra harness together? They are the same color wires. The little instruction that came with the Sony says connect blake wire (negative) first then yellow and red wires (+) last. Lastly, the antenna adaptor from Metra doesn't fit firm on the back of the stereo either.(Metra 40-GM10 GM Antenna Adapter). I called Metra they said this is the right adaptor. Do you have any idea how to fix this? Thanks for your help and input in advance.

Yes those harnesses get hooked wire to wire (matching color). You would do this with neither of them plugged in. Plug it in only after all the connections are made. The 70-2003 obviously plugs into the factory harness and the sony plug goes in the sony radio (obviously).  Either that car has a GM barb antenna adapter the one you list is correct for the normal GM antenna. The large motorola end goes into the sony radio and the gm antenna goes into the female end. It may also have a standard motorola end already there if it had the toyota antenna, or it may use the newer chrysler end. Post a pic and we can be of more help there.To master and control electricity is perfection. *evil laugh*

racerjames76, thanks a lot. the site don't let me download pic because of it's size. the gm antenna fits fine with metra 40-gm10 but since motorola end of metra 40-gm10 doesn't fit the sony. Do you think metra 40-gm20 radio antenna with mini adapter fits? or what do you think is best to do? Thanks for your help again.

The 40-gm20 is not the correct adapter. If the 40-gm10 doesnt fit properly there is either something wrong with the antenna adapter or the radio.

you will also need to connect the red ignition lead from the sony  to an ignition powered fuse in the fuse box as stated in the instructions with the supplied fuse tap and extension wire. the red wire in the 70-2003 does not connect to anything

I am pretty sure that the red wire of the 2003 is the switched wire.  You do not have to run a wire to the fusebox.

According to the photo i found online of the back of that radio, the motorola antenna end goes in to the left of the RCA jacks, the red and white set of 6 plugs (same as you would find on the back of all newer TV's.  There is a word "BUS" stamped on the radio directly to the right of the antenna port. Hope that helps...To master and control electricity is perfection. *evil laugh*

Thanks so much for all the input. I made it! I works great. just hooked up the metra harness and Sony harness together. The antenna is fine too. I was trying to hook it in a wrong spot. Special thanks to racerjames76!