Vehicles going head to head at game (8)
I believe the answer is:
baccarat
'game' is the definition.
(baccarat is a kind of game)
'vehicles going head to head at' is the wordplay.
I cannot really see how this works, but
'at' is found in the answer.
This may be the basis of clue (or it may be nonsense).
(Other definitions for baccarat that I've seen before include "Card game played in casinos" , "Casino card-game" , "Casino card game" , "Card game in which players bet against the banker" , "Card game in which punters gamble against the banker" .)