See a redhead in a vehicle (3)
I believe the answer is:
car
'vehicle' is the definition.
(I know that car is a type of wheeled vehicle)
'see a redhead' is the wordplay.
'see' becomes 'c' (the word for the letter, according to Chambers).
'redhead' becomes 'r' (the head/first letter of 'red').
'c'+'a'+'r'='CAR'
'in a' is the link.
(Other definitions for car that I've seen before include "Vehicle carrying vehicles" , "Automobile" , "One for the road?" , "Road vehicle; rail coach" , "Hatchback, say?" .)