I know this is an old thread, but the title is exactly the issue I'm seeing on my Coupe. For example, I checked the car today and the steering wheel, instrument cluster & dash were covered in condensation. This issue has surfaced just in the past 6 months or so. With the cold weather right now, condensation was really significant today. Had to wipe down the steering wheel, dash & instrument cluster. Felt the carpet and didn't detect any moisture which would indicate a drainage leak from elsewhere. All window seals look to be in good condition.

Storage Conditions: I keep the car parked in the driveway under a car cover as the garage is already full of other vehicles. I have stored it this way from the beginning (12 years of ownership). I also place a windshield screen inside the cabin.