well i cant stand it anymore my radio is liek 2x louder and my cd player is probably 3x louder and i have to turn the thing all the way up to get decent audio but it is stil not loud enough

i hav ethe blaupunkt sr04 and i have it connected through the aux imput on the dash and i have also tried playign it through the radio but still to no sound increase

is there some type of preamp that i can get that will amplify the sound coming out of the sirius tuner and be able to be safely run through my stock radio system that i hope on upgrading soon

This is what you need to tap into your aux from behind to boost the signal. I haven't got one myself yet, but plan to eventually.

http://www.discountcarstereo.com/detail.aspx?ID=317

Looks like that product only has RCA inputs and outputs. Does the Nissan OEM stereo have RCA jacks or do you have to do some cutting and splicing?