Hi,
Are there any good ground points in the trunk that can be used for caraudio ground wire?

Thanks,

 

Under the rear seats on the seatbelt bolt plate.

 

You want to keep the grounds as short as possible. For any equipment in the trunk, there are grounding points that Ford uses for the Sirius radio and Shaker 1000 options. Remove the trunk liner and on the passenger side metal trunk frame there should be a couple of empty threaded holes for bolts that can be used as a ground. If you have factory Sirius xm, the module will be there and grounded to one of the points.. You can add any ground wires to an existing ground or, if none of the grounds are being used, go to home depot and find a bolt that fits to make it a ground.