People carrier's small opening to reverse in a narrow street (9)
I believe the answer is:
aeroplane
'people carrier's' is the definition.
(vehicle which carries people)
'small opening to reverse in a narrow street' is the wordplay.
'small opening' becomes 'pore' (I've seen this before).
'to reverse' says the letters should be written in reverse.
'in' means one lot of letters goes inside another.
'narrow street' becomes 'lane' (a lane is a narrow road).
'pore' in reverse letter order is 'erop'.
'a'+'lane'='alane'
'erop' going within 'alane' is 'AEROPLANE'.
(Other definitions for aeroplane that I've seen before include "Fixed-wing aircraft" , "crate?" , "Flier" , "Lancaster?" , "Eg, jumbo jet" .)