Odd new jewel in car (6)
I believe the answer is:
dodgem
'car' is the definition.
(I've seen this before)
'odd new jewel' is the wordplay.
'new' is an anagram indicator.
'jewel' becomes 'gem' (synonyms).
'odd' anagrammed gives 'dod'.
'dod'+'gem'='DODGEM'
'in' acts as a link.
(Other definitions for dodgem that I've seen before include "Electric car" , "ride - with 14a" , "Small car at funfair for bumping into others" , "Fairground amusement vehicle" , "Car used in fairground" .)