An "in car" variety of dog? (5)
I believe the answer is:
cairn
'dog?' is the definition.
(cairn is a kind of dog)
'an in car variety' is the wordplay.
'variety' is an anagram indicator.
'in'+'car'='incar'
'incar' anagrammed gives 'CAIRN'.
'of' acts as a link.
(Other definitions for cairn that I've seen before include "Stone-pile monument" , "Mound of stones on mountain top" , "Stone mound" , "Man" , "Small terrier" .)