GM Service Manual Online
For 1990-2009 cars only
Figure 1:

Base of the "B"-Pillar behind the seat


Object Number: 530992  Size: LF
(1)Ground G205
(2)Radio Antenna Module
(3)Antenna coax to the radio
(4)Connector C301 -- Inline between the instrument panel harness and the LH seat harness
(5)Antenna coax to the front windshield
(6)Antenna coax to the rear windshield
Figure 2:

RH door speaker and the rear window antenna buffer


Object Number: 530995  Size: LF
(1)RF door speaker (LF door speaker similar)
(2)Antenna Buffer