In which American raced buggy? (4,3)
I believe the answer is:
used car
'in' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'american raced buggy?' is the wordplay.
'american' becomes 'us' (abbreviation for United States).
'buggy?' indicates an anagram (I've seen 'buggy' mean this).
'raced' is an anagram of 'edcar'.
'us'+'edcar'='USED CAR'
'which' acts as a link.
(Other definitions for used car that I've seen before include "Second-hand vehicle" , "Second-hand motor" , "Previously-owned motor" .)