Commercial car worker loses the head with ill temper (10)
I believe the answer is:
mercantile
'commercial' is the definition.
('mercantile' can be similar in meaning to 'commercial')
'car worker loses the head with ill temper' is the wordplay.
I cannot really see how this works, but
an anagram of 'car' is 'rca' which is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for mercantile that I've seen before include "Relating to (overseas) trade" , "Commercial" , "Relating to trade or commerce" , "Dealing with trade" , "concerning trade" .)