Article in a vehicle, of little weight (5)
I believe the answer is:
carat
'little weight' is the definition.
'carat' can be an answer for 'weight' (I've seen this before). I'm not sure about the 'little' bit.
'article in a vehicle' is the wordplay.
'article' becomes 'a' (the indefinite article in English).
'in' is an insertion indicator.
'a vehicle' becomes 'cart' (cart is a kind of vehicle).
'a' inserted into 'cart' is 'CARAT'.
'of' is the link.
Can you help me to learn more?
(Other definitions for carat that I've seen before include "Measure of weight of diamonds" , "Gem weight unit" , "Unit of weight of gemstones" , "Unit for precious stone weights" , "Metal weight" .)