Content to drool and release trapped gas, I carry a bit of excess (4,4)
I believe the answer is:
roof rack
'trapped gas i carry a bit of excess' is the definition.
I can't tell whether this defines the answer.
'content to drool and release' is the wordplay.
'content to' means to look at the middle letters (the contents of the word).
'and' is a charade indicator (letters next to each other).
'release' becomes 'frack' (I can't explain this - if you can you should believe this answer much more).
The centre of 'drool' is 'roo'.
'roo'+'frack'='ROOF-RACK'
Can you help me to learn more?
(Other definitions for roof rack that I've seen before include "Attachment to car" , "Bags I get on this" , "Framework for carrying things on car roof" , "Framework for carrying luggage on top of car" , "Framework to carry luggage on top of car" .)