Police car returns holding up houses (7)
I believe the answer is:
terrace
'houses' is the definition.
(I've seen this before)
'police car returns holding up' is the wordplay.
'holding' indicates a hidden word.
'up' is a reversal indicator (in down clue: letters go upwards).
'ecarret' is hidden in the letters of 'police car returns'.
'ecarret' written backwards gives 'TERRACE'.
(Other definitions for terrace that I've seen before include "Row of housing" , "stand" , "platform" , "Group of non-detached houses" , "Stadium spectators' area" .)