I did this write-up on escape-central.com and thought I would post it here as well in case anyone was interested in installing a SAT antenna. I chose to mount mine on the back of the roof and run the wiring through the rear hatch. The antenna cable was plenty long to make it all the way to the dash. I actuallytucked the cable under and through the black rubber gasket around the hatch. The gasket is held in place by some very gooey black stuff. It is not like a permanent adhesive, rather just a real gooey mess. You will get it on your hands and the wire so make sure to clean it off before touching your interior.
(My Host is having some service problems at the moment so if the pics aren't showing up just check back later).
1. Antenna mounted on the back of the roof centered on the vehicle. You can see where it is mounted so that the plastic wire cover wraps right over the edge of the roof into the hatch area.
2. You can see here where the wire runs down into the hatch area and is taped along the curve to prevent the hatch from rubbing when opened/closed.
3. Another shot of the wire taped down tucked in underneath the gasket. The gasket basically is "U" shaped and slides onto the flat sheetmetal. I tucked the wire under one 'leg' of the "U" and ran it down to the lower left corner.
4. Here is the gasket pulled away from the sheetmetal in the lower left corner. you can see where the wire wraps around the sheetmetal and comes inside of the gasket.
6. The wire now runs under the sill trim which pops up in the corner with slight tugging (you don't need to remove the whole piece.)
7. Then I routed the wire under the corner of the cargo area and beneath the plastic paneling on the side. Mine is a little different b/c it is a Hybrid and the battery is beneath the carpet but you should be able to tuck the wiring beneath the side panels without a problem. The wires then continue alongside the back seat and under the trim of the doorsills up to the bottom left of the dash. From here your options are nearly endless as the dash is very open underneath.

-Tim
2006 Mercury Mariner Hybrid AWD
Black with Pebble interior
Premium Package with Nav & Moonroof
Current ODO:
26,152
Typical Drive: 20 min crosstown in heavy traffic (3.5mi there and back twice a day)
532 Gallons of gas saved
That's 10,642 lbs less CO2 emitted