an electric motor for applying an electric steering assist to {TAIL ~ a steering system} of {HEAD ~ the vehicle} 
an electric motor for applying an electric steering assist to { TAIL ~ a steering system } of { HEAD ~ the vehicle }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD