C220 W203 Rear Door Speakers

[aspguitars]

Hi! my rear door speakers are making terrible noises. I'm pretty sure that they are blown. Can anyone tell me what size they are and if possible what speakers will fit. I'm going to have to take the door card off eventually, but as yet have not. I found a company on Ebay that claim to have replacements, but I'm not sure of the sizes. Any help would be appreciated
Ade