Goods in vehicle on journey (5)
I believe the answer is:
cargo
'goods' is the definition.
(cargo is a kind of goods)
'vehicle on journey' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'on journey' becomes 'go' (I've seen this in other clues).
'car'+'go'='CARGO'
'in' acts as a link.
(Other definitions for cargo that I've seen before include "Consignment" , "Goods carried by a large vehicle" , "Payload" , "Freight, load" , "Goods in transit" .)