Mouse-like squeaking coming from C43 dash that goes away when wet...

[DieselHead]

I've had a few problems with my 1999 C43 but this one is the worst: something in or around the dashboard area has developed a pretty persistent squeaking that sounds like a mouse. It's pretty much squeaking all the time because of the stiff suspension that causes the car to move around a lot.

The only way I have found to silence it (and only sometimes) is to run my windshield wipers with wiper fluid. I assume that something with the fluid flowing down there somewhere quiets it. Anyway, it's really annoying and it needs to be fixed. It's embarrasing.

Anyone have any experience with something like this?

Thanks!

Alex