I have had Sirius installed for a couple weeks now with the antenna mounted on the front of that dash and have been experiencing numerous dropouts of the signal. I know that I need to mount the antenna behind the OEM antenna on the roof. I have figured out how to run the antenna to the back, up into the headiner and out the gasket that the wires that run to the boot are in. The question that I have is...Do I need to do anything to keep water from entering the gasket since there will be an antenna wire coming out from underneath it? Is there some sort of sealant that I can use. The last thing I want is to have a rusty mini or an electrical problem because I installed Sirius.
Thanks,
Justin

 

oooh I know this one. any of that ge stuff u can get from home depot will work. the clear stuff for a bathroom works pretty will if your scard about water just a few drops is all u need

 

You should be mostly OK, especially with such a thin antenna cable. I have a thicker cable running over the boot seal for my laser detector and it is fine.
You might want to buy some Goop (available in the glue section of most stores) or other flexible glue, to seal up any areas where it enters or exits.
I have a few more ideas on antenna mounting here if you wanted to try elsewhere, but the rear roof is probably the best location as far as reception is concerned.
(Do you have a sunroof? You can mount it inside the rear one, on the corner, facing up...)