Returning in a public vehicle one tabloid shows a cocktail (9)
I believe the answer is:
margarita
'a cocktail' is the definition.
(margarita is a kind of cocktail)
'returning in a public vehicle one tabloid' is the wordplay.
'returning' says the letters should be written in reverse.
'in' indicates putting letters inside.
'public vehicle' becomes 'tram' (I've seen this before).
'one' becomes 'i' (Roman numeral).
'tabloid' becomes 'rag' ('rag' can be a synonym of 'tabloid'**).
'a'+'tram'='atram'
'i'+'rag'='irag'
'atram' placed around 'irag' is 'atiragram'.
'atiragram' backwards is 'MARGARITA'.
'shows' acts as a link.
(Other definitions for margarita that I've seen before include "Tequila-based cocktail" , "Cocktail consisting of tequila and lemon juice" , "Spanish girl" , "Stiff drink" , "Type of tequila cocktail" .)