I agree not to put it in the trunk. Makes taking hostages difficult. Their cries for help can sometimes transmit over the radio during satellite acquisition..
But yeah I installed the Sirius unit itself in the trunk, then mounted the antenna on the back shelf with velcro. There was no way my dumb ass was going to mess with the window seals. I was able to squeeze the antenna wire through a gap behind the rear seat from the trunk, as shown in the 2nd pic. My car was similar to yours, might be worth a look. Works fine, safe from weather/theft/damage/whathaveyou.
