side repeater condensation.

Anyone experienced condensation in their side repeater? My drivers side is about an 8th full of water. Prob getting too close with jet wash. I noticed it when i bought the car it was half full. The stealer said they have put a new one on....could this be a warrenty claim?

If not how easy is to put a new one in. Im assuming the wheel arch lining will have to come off.

So far ive attempted drying it out with a hair dryer...only limited success with that lol.