Renault Clio wiper linkages

[mattie]

Hi all
My friend has an R Reg Clio 1.4, and the driver side windscreen wiper managed to disconnect itself from the mechanism and pivot past the side of the windscreen. There was also a smell of burning, not unlike a scalextric set.
I had a look under the panel where the jack is housed, the linkage from the motor had fallen/popped off the end of the wiper arm. It's fitted via a hard plastic plug that has two protuberances at around 120 degrees apart. This plug fits into a hole with two slots on the wiper arm. The problem is that the plug doesn't feel very secure, and prone to jumping off the arm. I was thinking the plug might require twisting to fully locate, as the protuberances would not be over the slots and hence would be firmly fixed, but no matter how hard I tried it wouldn't twist. I thought there might be a circlip or some other fastener, but I can't see where it would go. I can't check the passenger side linkage as it is pretty inaccessible unless I take off the plastic cover, which I'm loath to do as the windscreen rubbers are on it.
Does anyone know how these clips are supposed to be properly fixed? I've put everything together, and the wipers are fine, but it feels insecure, to say the least.
Also, the motor was stinking as the linkage had jammed up the mechanism, it works now but is there any chance of unseen damage that might be problematic later that could be easily fixed now?
All advice gratefully received
Matt