Pick up car with enthusiasm (5)
I believe the answer is:
heart
'enthusiasm' is the definition.
(thesaurus)
'pick up car' is the wordplay.
'pick up' becomes 'hear' (hearing is a kind of picking up).
'car' becomes 't'.
'hear'+'t'='HEART'
'with' acts as a link.
(Other definitions for heart that I've seen before include "Vital organ - centre - courage" , "Middle" , "Cardiac courage" , "Player for Scottish team" , "one in suit" .)