signal problem in car

i have a 2002 tdi jetta have tried on hood behind the roof antena on fender

the signal works 90% of time but comes and goes sometimes it's perfect depending on where you are traveling wondering does weather affect thes items i would like to know best place ton install antenna

best reception i got was on hood under my bug deflector

am a canadian stuck with xm canada


any info appreciated


thank you

What I am wondering is how you listen to the radio. Do you use the built in FM transmitter or do you use some other form of audio input into the VW, like an auxiliary input or something. I only ask because sometimes people confuse FM static with satellite radio signal loss. And, where in Canada are you?