Service small cars before test (8)
I believe the answer is:
ministry
'service' is the definition.
(thesaurus)
'small cars before test' is the wordplay.
'small cars' becomes 'minis' (I've seen this before).
'before' means one lot of letters go next to another.
'test' becomes 'try' ('try' can be a synonym of 'test').
'minis'+'try'='MINISTRY'
(Other definitions for ministry that I've seen before include "Priests' work" , "Government building" , "Government employees" , "service" , "church" .)