It might be a stretch (4)
(Other definitions for pose that I've seen before include "'Present, a problem say (4)'" , "Sit for picture" , "Stance - attitude" , "Sit for a painter" , "Pretend to be somebody else" .)
'it might be a stretch' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for limo that I've seen before include "Stretched car, often used for partying" , "Luxurious car (colloq.)" , "Stretched car (abbr)" , "Long motor" , "Luxury car" .)