i've got this car years ago. There were 2 connectors: 1 with 6 pins that is the one you have (for the speakers, I use 2 channels in the front couse I put the tweeters too..), and another one with 3 or 4 (i don't remember), with the ground, the remote control and the 12 V.
The antenna cable was detached.
I think you have to check your cd's plug to check, couse they change from a brand to another!
Hope to help