Vauxhall car approaching yard is off course (6)
I believe the answer is:
astray
'off course' is the definition.
(to be led astray is to be led off course)
'vauxhall car approaching yard' is the wordplay.
I cannot quite see how this works, but
'car' could be 'astra' (I've seen this before) and 'astra' is found in the answer.
'yard' could be 'y' (abbreviation) and 'y' is present in the answer.
No letters remain.
This explanation may well be incorrect...
'is' is the link.
Can you help me to learn more?
(Other definitions for astray that I've seen before include "Gone off the right path" , "Away from the right path like a satyr (6)" , "Wandering, errant" , "Up the garden path?" , "Like carrier" .)