Sorry guys but I figured best to separate the two questions :)

1994 540i right hand drive:
My drivers side wiper shudders on the way back, the head is brand new, blades are new, it appears that there is wear in the drive mechanism of the wiper motor assembly, is this the issue here?

Any good tips on removing the wiper drive assembly? I have the tools to be able to mill out the housing and sleeve the output shafts if wear is a problem, but easier options are very welcome!

Replacing the wiper drive mechanism with a good S/H unit would likely be the easiest if it is the issue, but what to look for when buying a s/h motor assembly??