Ok, I have only had my SS since December and my LT didn't have a sunroof. I was in a touchless carwash for the first time with it and i had the sunroof closed but the headliner slide open. well i heard water dripping really good through the rear of the sunroof when the jets hit the top of the car. very well actually like a slow faucet. I stuck my fingers up there and felt water and freaked out and jammed a microfiber to catch the water (i'm sure like an idiot). The headliner didn't get wet so i guess it drained properly. I've had sunroofs before from GM and never experienced that.

Is this normal? so it should leak in like that then drain? Like I said, this may be a stupid question but I've never had that happen before with a sunroof.

 

While parked, open the sunroof and look in the 4 corners. You will see that the drain holes are technically inside the car. Sounds like the sunroof glass wasn't sealing real good and the water squeezed by. But it also sounds like the drains did their job.
I've never heard any water dripping on mine. But I don't drive in rain if possible and never use a car wash. Mine has been literally flooded by me when hand washing but never seen any leakage.
Check the sunroof seal area for any foreign object(leaf etc.) stuck to the seal that would let water pass inside.

 

If you push on the glass you'll find that its not exactly a super tight seal..closing the doors will make it move from air pressure..I would refrain from doing any kind of pressurized washing in this area..while it will seal under normal water conditions, pressurized water will find its way thru..which is why you never use this around bearing seals or lube points with rubber boots. Yes, the drains are for this..it keeps the water out of the interior and routes it outside. As part of regular maintenance, need to make sure these drains remain clear, especially if you open the glass often.

 

Yeah, the sunroof glass has a "gravity seal" for the lack of a better term, so it can be blasted open a tad with high pressure water.

Check the drain holes for blockages, you can use compressed air to gently blow the lines out....but be careful, a full on blast of shop air can blow the tubes off making for some less than fun work putting them back.