Abstract: Kits for vehicles may include pulse-width-modulated solenoids configured to selectably turn individual nozzle assemblies on and off and vary their flow rates when installed in fluid communication with the nozzle assemblies, one or more wirelessly-controllable solenoid controllers, a wiring harness to electrically connect the pulse-width-modulated solenoids to the controller(s), a wirelessly-communicating GPS antenna system, a LiDAR sensing system which may be wirelessly-communicating, associated wiring and bracketry to connect the kit with a vehicle, and a mobile device configured to wirelessly cause the one or more controllers to turn individual nozzle assemblies on and off and vary their flow rates based on sensed data and/or recorded data, in view of user-selected criteria.