I recommend that the various people in this group who have made these observations call them in to the Fremont P.D.
Call their normal business line at 790-6800 and ask to whom you can relay this information. Let them know that these people are being seen by others and probably are frequenting our neighborhood as a place to commit some sort of petty crime. Provide as much descriptive detail as possible.
It sounds to me like we have some people who are using their cellular phones to line up drug deals and then moving their behicle location around our neighborhood over time to minimize the risk of arrest.
As far as the loud stereo goes, the police officers with whom I've dealt on numerous petty crime issues all say that these petty criminals aren't too bright. Take for example the taggers who were spraypainting their initials or tags in the same neighborhood where they were committing home and auto burglaries. Who else but a peabrain would get a rise out of spraypainting their initials all over town??
And, I second that recommendation of trying to get a license plate number and the best possible vehicle/driver descriptions possible.
Del at The Trees
P.S. And anytime that someone is stopped in the middle of the street with a blaring stereo going, you should call the cops. Don't try to confront them in person. You have no idea who you would be dealing with or how loaded on drugs/booze they might be! Bear in mind the account on here earlier this summer about the resident who went out to tell someone to go away and who had a gun pulled on him.