Hit by a car - not at all well (3,4)
I believe the answer is:
run down
'hit' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for run down that I've seen before include "synopsis" , "Disparage" , "brief summary" , "In a neglected state" , "Drained" .)