Manage to smuggle uranium in car (5)
I believe the answer is:
coupe
'car' is the definition.
(coupe is a kind of car)
'manage to smuggle uranium' is the wordplay.
'manage' becomes 'cope' (synonyms).
'to smuggle' means one lot of letters goes inside another (smuggle can mean to secretly carry).
'uranium' becomes 'U' (U is the chemical symbol for uranium).
'cope' going around 'u' is 'COUPE'.
'in' is the link.
(Other definitions for coupe that I've seen before include "Car with just two doors and two front seats" , "Dessert dish" , "Two-door car" , "Car; dessert glass" , "Type of car; dish" .)