Man I flipped in posh car (5)
I believe the answer is:
roger
'man' is the definition.
(I've seen this before)
'i flipped in posh car' is the wordplay.
'i' becomes 'ego' (I've seen this before**).
'flipped' says the letters should be written in reverse.
'in' indicates putting letters inside.
'posh car' becomes 'rr' (I've seen this in other clues).
'ego' written backwards gives 'oge'.
'oge' put within 'rr' is 'ROGER'.
(Other definitions for roger that I've seen before include "I've got the message" , "I get you" , "Boy - received and understood" , "Boy's name - I will do what you say" , "Expression of agreement" .)