Chap carrying 75% of cargo in top-notch vehicle (9)
I believe the answer is:
ambulance
'vehicle' is the definition.
(ambulance is a kind of vehicle)
'chap carrying 75 of cargo in top-notch' is the wordplay.
I cannot quite understand how this works, but
'chap' could be 'lance' and 'lance' is located in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ambulance that I've seen before include "Emergency vehicle" , "Vehicle for sick or injured" , "what's used by 9a 19d" , "It will bring you to hospital" , "one seen by accident" .)