Most shocking incident for me in DC. Went to the museums on the mall with friends. Well one was from Vermont, she left her wallet VISIBLE on the back seat. Plain view. Shockingly, no one broke into my car to get it.
Only time I have had my car broken into was in baltimore on a side street. I didn't leave anything in view, hid all well before I parked.
Hiding stuff in advance is usually good enough. Don't park and put a purse or other valuable in the trunk, yes it is out of view, but still it is known to be there.
Rule of thumb, if the incident doesn't make the paper it was nothing serious, was in vegas this past weekend and the mart across the street from our hotel was blocked off with police tape and about 12 cop cars. Never made the news, guess it wasn't that bad...