Speaker static

I have an 03 jetta with monsoon sound system. The tweeter and base speakers in the passenger door have static sometimes. Once the static starts it won't go away until the next time I drive, or worse it won't go away for weeks. It even has the static when the engine is off sometimes. Any ideas? Also I took the dash apart and I can't figure out how to get the radio loose from the pieces on the bottom... is there a latch or something? Thanks