I have compared the wiring diagram and the pinouts that Paul posted. The pinouts are correct, however not all of the pins labeled in those pinouts apply to your car. For example the rear speaker outputs are not available on your car, the BOSE wire, etc.
It looks like all of the wires that you need (audio signals to the amp, amp turn-on, front speaker connections) are available in the dashboard. Crutchfield has a wiring harness for some of the dashboard connectors, but it doesn't appear to have one of the connectors that you would need. Because you are only connecting to about 8 wires and this adapter would only help you with 4 of those, it is probaby best to just tap into only the wires that you need. Here is that adapter: