I've had my crossfire coupe a couple months and already had the passenger side floorboard flooded by this issue. Changed cabin filter and followed the above directions to clean out the drains. Shop vac will help but you still need to rod out the debris below the plug/hole level. I poured water through and made sure it drains out the bottom of the fender to make sure it isn't backing up. I will vac it out often and test with a gallon of water.
I just resoldered the RCM and wish I had done it sooner, was stranded after the car died suddenly on the road. Two cel warnings pointing to the AIR system and I waited as I didn't come back on for a while. Live and learn! She's driving good again now. Just ordered the Eurotune May special! That's next.