Which make of car ? There used to be a chap down Broomhill (may have shut) who did VW parts. Other than that, have a drive down Carlton, plenty to go at.
Try these.... http://www.247spares.co.uk/ I get all my spares from here- they are brilliant. Basically they send an email to scappers nationwide and whoever has your part contacts you directly. All happens in less than an hour.
RE: Broomhill one definately shut Why not ? Barnsley Council is executing a policy of obliterating the green belt in my opinion.
RE: Try these.... Brilliant place just outside Doncaster at a place called Toll Bar just other side of Bentley all parts on shelf no messing about taking parts of your self.