Drivers who park closer up the side of your car than necessary.
The evil cousin of the above, the careless munter who opens his/her car door onto yours.
Cyclists who appear out of the blue in queuing traffic and pass within millimeters of your bodywork.
Comments from passers-by when you're washing your car to the effect of "you can do mine when you're finished!". Hardy. Hardy. Har.
Digital roadside signs that display useless information that does nothing more than distract drivers - they could at least flash jokes up there, or a weather forecast, or fitbaw scores (or even nikked wummins, if the technology's up to it?).
Gritters spraying the highways on dry evenings when it would be warm enough to take the bins oot in yer kekks.
Folk who never indicate the direction they are going