Water damage to window regulators
 

Hi. I'm new to this and don't know much about my C250 TD estate (my first Mercedes) but I've got a problem at the moment that seems a bit strange.
I've occasionally had dashboard lights (eg brake failure) lights come on for no good reason, then disappear if the ignition was turned off and turned back on. Then my front electric window stopped working, was 'reprogrammed' and went again 3 days later. Then the central door locking stopped working.
The dealership has said that I need 2 window regulators, which have been water damaged, and that the electrical peculiarities are due to the problem with the regulators.
I'm concerned that I've got water damage in a 3.5 year old car, and that the problem might re-occur in a relatively short period of time. Anyone else had the same sort of problems?

Thanks for any help