Arrange to make a vehicle costlier (3,2)
I believe the answer is:
rig up
'arrange' is the definition.
The definition and answer can be both to do with creating things as well as being verbs in their base form.
Perhaps there's an association between them I don't understand?
'a vehicle costlier' is the wordplay.
'a vehicle' becomes 'rig' (rig is a kind of vehicle).
'costlier' becomes 'up' (I can't justify this - if you can you should give a lot more credence to this answer).
'rig'+'up'='RIG UP'
'to make' is the link.
Can you help me to learn more?
(Other definitions for rig up that I've seen before include "Put (structure) together" , "Make temporary arrangement" , "Cobble together" , "Erect quickly and insubstantially" , "Assemble (something) in a makeshift way" .)