I've had the same problem since new with my bike. The dealer tried to fix it with the undo & wiggle a bit but...no luck... Tried WD40 only worked for 2days and made a big mess.
Only way I could stop it was undo the cover, slide down and stick some silicon grease in there. This worked for 4months and just started making the squeak again today.
I spent ages trying to find the cause and I think it's because the cover is a little out of round, if you squeeze it a certain way it stops but soon as I let go starts again. It's only the left side that squeaks on mine but sure is annoying, particularly for a sound engineer.
If you come up with a more permanent solution let us know.
