Vehicle turned up to rescue suspect seen round old track (10)
I believe the answer is:
racecourse
'old track' is the definition.
'racecourse' can be an answer for 'track' (thesaurus). I am unsure of the 'old' bit.
'vehicle turned up to rescue suspect seen round' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'turned up' is a reversal indicator.
'to' becomes 'o' (I can't justify this - if you can you should believe this answer much more).
'suspect' is an anagram indicator.
'seen round' is an insertion indicator.
'car' reversed gives 'rac'.
'rescue' anagrammed gives 'ecurse'.
'o' placed inside 'ecurse' is 'ecourse'.
'rac'+'ecourse'='RACECOURSE'
(Other definitions for racecourse that I've seen before include "Venue for meeting" , "Aintree, for example" , "Running track for horses" , "Eg, Aintree" , "Hippodrome (originally)" .)