Old car in America: something blown? (7)
I believe the answer is:
ocarina
'something blown?' is the definition.
(ocarina is a kind of wind instrument)
'old car in america' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'america' becomes 'a' (common abbreviation - e.g. in organisation names).
'o'+'car'+'in'+'a'='OCARINA'
(Other definitions for ocarina that I've seen before include "Small egg-shaped wind instrument with holes for the fingers" , "Egg-shaped wind instrument with finger holes" , "Toy flute" , "Wind instrument with a mouthpiece and finger holes" , "Bird-shaped flute" .)