Quickly getting in a large car (6)
I believe the answer is:
saloon
'car' is the definition.
(I've seen this before)
'quickly getting in a large' is the wordplay.
'quickly' becomes 'soon' (I've seen this in other clues).
'getting in' indicates putting letters inside.
'large' becomes 'l'.
'a'+'l'='al'
'soon' enclosing 'al' is 'SALOON'.
(Other definitions for saloon that I've seen before include "An American pub, as in the wild west" , "Lounge bar" , "Describing a bar - describing a car" , "Large public room" , "Car with separate boot" .)