Epitome of a popular motor race (11)
I believe the answer is:
incarnation
'epitome' is the definition.
(I've seen this before)
'a popular motor race' is the wordplay.
'a popular' becomes 'in'.
'motor' becomes 'car' (I've seen this before).
'race' becomes 'nation' (I've seen this before).
'in'+'car'+'nation'='INCARNATION'
'of' is the link.
(Other definitions for incarnation that I've seen before include "Epitome" , "Personification of an abstract idea" , "Existence" , "Living embodiment of, eg, a deity" .)