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