violating vehicle; vehicle in violation
Typically used for vehicles that violate parking regulations, but can apply to other traffic violations. Often seen in official notices or news reports.
We will crack down on violating vehicles.
The illegally parked vehicle was towed away.
駐車違反 is the act of illegal parking; 違反車 is the vehicle itself that is in violation, often as a result of such an act.
Compound of 違反 (violation) and 車 (vehicle). The exact historical derivation is uncertain, but the word follows a common pattern for forming nouns describing entities involved in an action.