Oppose pilot with car entering races (10)
I believe the answer is:
controvert
'oppose' is the definition.
(synonyms)
'pilot with car entering races' is the wordplay.
I cannot really see how this works, but
'car' could be 'rover' (former British car manufacturer) and 'rover' is located in the answer.
'races' could be 'tt' (Isle of Man Tourist Trophy races) and 'tt' is located in the remaining letters.
The remaining letters 'con' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for controvert that I've seen before include "Wrangle" , "Argue against" .)