Beastly sort of business working in support of roadside assistance provider (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

CO (abbreviation for company or corporation = business) + ON (working), after (below, in a down clue = supporting) RAC (roadside assistance provider, originally owned by the Royal Automobile Club which still exists as a private club for motor enthusiasts). A sort of beast.