Vehicle husband used in wild, uncultivated country (4)
I believe the answer is:
bush
'wild uncultivated country' is the definition.
(as in the Australian bush)
'vehicle husband' is the wordplay.
'vehicle' becomes 'bus' (public transport vehicle).
'husband' becomes 'h' (abbreviation).
'bus'+'h'='BUSH'
'used in' is the link.
(Other definitions for bush that I've seen before include "Shrub; protective sleeve" , "Low, woody plant" , "Outback" , "ex-president" , "part of shrubbery" .)