Some standing in the vehicle (4)
I believe the answer is:
trap
'the vehicle' is the definition.
(trap is a kind of vehicle)
'some standing' is the wordplay.
'some' becomes 'part' (only part of something).
'standing' shows that the letters should be reversed in order (in a down clue, letters stand up).
'part' in reverse letter order is 'TRAP'.
'in' is the link.
(Other definitions for trap that I've seen before include "Snare; pony carriage" , "mug" , "Golfing hazard" , "Baited device" , "that may be sprung?" .)