Racing track could make you crown a career (6,3)
I believe the answer is:
cresta run
'racing track could make' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'crown a career' is the wordplay.
'crown' becomes 'crest' (synonyms).
'career' becomes 'run' (career can mean to run or move out of control).
'crest'+'a'+'run'='CRESTA RUN'
'you' acts as a link.
Can you help me to learn more?
(Other definitions for cresta run that I've seen before include "Swiss skeleton toboggan track" , "Frozen channel" , "tobogganing slope" .)