Small car in jam in Ireland (4)
I believe the answer is:
mini
'small car' is the definition.
(I've seen this before)
'in jam in ireland' is the wordplay.
'in' indicates a hidden word.
'MINI' is hidden within 'jam in ireland'.
(Other definitions for mini that I've seen before include "(Car etc) of small size" , "vehicle" , "type of garment" , "Baby" , "Short skirt - small car" .)