Scene of intense activity within McLaren Automotive (5)
I believe the answer is:
arena
'scene of intense activity' is the definition.
(an arena might host a sporting competition)
'within mclaren automotive' is the wordplay.
'within' says the answer is hidden in the clue.
'ARENA' can be found hidden inside 'mclaren automotive'.
(Other definitions for arena that I've seen before include "Where one may find sportsmen" , "Engagement ring" , "Venue for boxing, circus and other action events" , "battlefieId" , "Place of activity, especially conflict" .)