the best way to mount is using a cup holder mount
like this item on ebay
Car Cradle & Cup Holder Mount for SIRIUS STARMATE STR1 - eBay (item 170198188123 end time Mar-07-08 17:05:53 PST)
that way you can run the cables behind the dash the antenna wire can go behind the glove box and up by the a pillar ( window pillar) remove the passenger sun visor and pull the antenna out of the sunroof mount it in the middle most of them have magnetic
also the best way to feed the audio in to the radio is by using the aux or the sat plug on the back of the radio, to listen to your Sirius you press the MODE BUTTON
you need this interface (fm modulators have a very bad sound quality when driving )
good luck
PIE CHRY04-AUX/S CHRYSLER AUXILIARY INPUT ADAPTER