Check car before start of travel (5)
I believe the answer is:
audit
'check' is the definition.
(an audit is an examination or check)
'car before start of travel' is the wordplay.
'car' becomes 'audi' (Audi is a German car brand).
'before' says to put letters next to each other.
'start of' suggests taking the first letters.
The initial letter of 'travel' is 't'.
'audi'+'t'='AUDIT'
(Other definitions for audit that I've seen before include "Financial inspection" , "Check of books" , "vetting of books" , "special ale" , "Examine account" .)