Check German car model (5)
I believe the answer is:
audit
'check' is the definition.
(an audit is an examination or check)
'german car model' is the wordplay.
'german car' becomes 'audi' (I've seen this in another clue).
'model' becomes 't' (Ford Model T car).
'audi'+'t'='AUDIT'
(Other definitions for audit that I've seen before include "Thoroughgoing check" , "Official inspection of company accounts" , "Examination of accounts" , "review of books" , "Go over" .)