It's done when there's a blast of fresh air in an open vehicle (8)
I believe the answer is:
swindled
'it's done when there's a blast of fresh' is the definition.
I can't tell whether this definition defines the answer.
'air in an open vehicle' is the wordplay.
'air' becomes 'wind'.
'in' means one lot of letters goes inside another.
'an open vehicle' becomes 'sled' (sled is a kind of vehicle. I am not sure about the 'open' bit.).
'wind' put into 'sled' is 'SWINDLED'.
Can you help me to learn more?
(Other definitions for swindled that I've seen before include "Ripped off" , "Defrauded" , "taken for a ride" , "Cheated (someone)" .)