I don't blame it, I don't like working in the cold either..

 

You are going to need a new amp man. I replaced mine with a new one and it has worked great since. Unless you somehow see a loose connection when you take apart the back left of the trunk, replace your amp and you'll be fine.

 

I was having the same exact problem with the G i bought a few days ago. New amp fixed the issue though. These cars are ~10 years old so no surprise that the amp is failing really.