Pops round for car ride (4)
I believe the answer is:
spin
'car ride' is the definition.
(as in taking a car for a spin)
'pops round' is the wordplay.
'pops' becomes 'nips' (as in nipping or popping round somewhere).
'round' is a reversal indicator.
'nips' reversed gives 'SPIN'.
'for' is the link.
(Other definitions for spin that I've seen before include "Political treatment by "doctor"" , "certain doctors initiate?" , "Gyrate, reel" , "Short pleasure trip" , "Twist - creative media relations" .)