determining {HEAD ~ a second test toe angle} of the second wheel relative to {TAIL ~ a second toe angle reference point} 
relative to
determining { HEAD ~ a second test toe angle } of the second wheel relative to { TAIL ~ a second toe angle reference point }
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL