These are retarded coaches of regular M/E trains whch has been modified into Parcel Van to haul automobiles (mostly Maruti)!!
All windows/door get jammed & reinforced, while there exist load/unload facility @ vestibule end, whch can b fully opened, as whn required!!
These coaches smehow can run @ speed higher as compared to Freight Wagon along with faster Load/unload & hence devised frm old Pass Coaches!!