Vehicle at rest broken down, one held up (6,3)
I believe the answer is:
estate car
'vehicle' is the definition.
(estate car is a kind of vehicle)
'at rest broken down one held up' is the wordplay.
'broken down' indicates anagramming the letters.
'one held' is an insertion indicator.
'up' becomes 'eca' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'at'+'rest'='atrest'
'atrest' anagrammed gives 'estatr'.
'estatr' going around 'eca' is 'ESTATE-CAR'.
Can you help me to learn more?
(Other definitions for estate car that I've seen before include "Station wagon" , "Spacious vehicle" , "Vehicle with large area for goods" , "Vehicle with five doors" , "Vehicle for passengers with goods" .)