What to do with broken down car, namely? (2,3)
I believe the answer is:
to wit
'namely?' is the definition.
('to wit' can mean namely)
'what to do with broken down car' is the wordplay.
I cannot quite understand how this works, but
'to' is found in the answer.
'with' could be 'w' (abbreviation) and 'w' is present in the answer.
'car' could be 't' and 't' is found within the answer.
A single letter 'i' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
(Other definitions for to wit that I've seen before include "i.e." , "Namely" , "specifically" , "In other words" , "That is to say" .)