Street cred possibly involves a hush-hush manufacturing advantage (5,6)
I believe the answer is:
trade secret
'hush-hush manufacturing advantage' is the definition.
'trade secret' can be an answer for 'advantage' (I have seen 'competitive advantage' mean 'trade secret' so perhaps 'advantage' could also mean 'trade secret'). I'm not sure about the 'hush-hush manufacturing' bit.
'street cred possibly involves a' is the wordplay.
'possibly' is an anagram indicator.
'involves' indicates putting letters inside.
'street'+'cred'='streetcred'
'streetcred' is an anagram of 'trdesecret'.
'trdesecret' enclosing 'a' is 'TRADE SECRET'.
Can you help me to learn more?
(Other definitions for trade secret that I've seen before include "Something company protects from competitors" , "competitive advantage" , "Confidential commercial information" , "wrinkle?" , "Company's protected information" .)