Quote: On the D80, is there a safety shift type of thing which will override the settings if that's going to result in over/under exposure? This might be a reason why you tell it to open the shutter for thirty seconds and it does something else.
Could be right....the headlights in the pic are probably a bit too bright already. It maybe that the scene is simply too bright to allow for a 30 second exposure.
Snowqueen - do you have a polariser? You could fit that to make things darker and give you a longer shutter speed. (ideally a ND (neutral density) filter would be used to darken things for longer shutter speeds but a polariser might do the job).
Another common subject to try longer shutter speeds on is moving water....do you have a stream or river nearby? (although I admit I am a bit of a sucker for blurry water )
EDIT - also, did you use f/22? Normally I wouldn't want to stop down so far but for this kind of thing I'd make an exception.