Here are the answers to the clues. (Thanks to Alconja in the Sphinx's Lair and boboquack here, for spotting #7 after I was unable to!)

>! 1 CO-IGNITION  
>! 2 NOTING ICON  
>! 3 CITING COON  
>! 4 COINING TOO  
>! 5 ONGOING TIC  
>! 6 NO-GIN TONIC  
>! 7 NOTICING IO
>! 8 I, COTTON GIN (!)  
>! 9 INTO COOING

These have

>! common letters INCOGNITO; and their extra letters, in order ... are also INCOGNITO. (Neat!)

So presumably the intended final answer is

>! INCOGNITO (although COGNITION, which is its anagram, *could* be an alternative answer).