Arab with small German car (5)
I believe the answer is:
saudi
'arab' is the definition.
(someone from Saudi Arabia)
'with small german car' is the wordplay.
'with' means one lot of letters go next to another.
'small' becomes 's' (abbreviation - e.g. clothes size).
'german car' becomes 'audi' (I've seen this in another clue).
's' next to 'audi' is 'SAUDI'.
(Other definitions for saudi that I've seen before include "One from Riyadh" , "Native of Riyadh, possibly" , "one accustomed to hot, dry conditions?" , "Eg, native of Riyadh" , "M East citizen" .)