Illicit trade in vehicles (7)
I believe the answer is:
traffic
This clue could be a double definition.
'illicit trade' is the first definition.
'traffic' can be an answer for 'trade' (I've seen this before). I'm unsure of the 'illicit' bit.
'vehicles' is the second definition.
(I've seen this before)
'in' is the link.
Can you help me to learn more?
(Other definitions for traffic that I've seen before include "Deals" , "used cars" , "Lots of vehicles" , "Group" , "Deal in, trade" .)