Audio Systems: sirius radio brain box problem, radio brain, sirius radio

Question
Taurus 2005
I had a sirius installed a couple of years ago and all was well until recently.  It started by having a signal problem and then went out totally.  I took it back to circuit city for repair and trouble shooting.  They informed me that moisture has caused a corrosion problem and a new brain box could probable solve the problem.
My question,is it cost effective to purchase a brain box(and where would I purchase it)have it installed or just buy a updated sirius radio?
Also is there a better place to install the radio since the guts of the car radio are in the trunk.
Thanks for any information you can give me.

Answer
the radio needs to be in the trunk next to the for amplifier
or you can buy a small portable sirius unit nd installe it at front with a car kit
it will be best also to buy a auxiliary input interface that way you can hear the sat radio  using the cd changer port
good luck