As a new recruit to Copen World I guess I have missed a whole bible full of advice on how to deal with water in the boot! when i bought my Copen it had been standing outside for 3 to 4 years and had a boot half full of water! It seemed to get in easily but then didnt drain away. Found the drain plug grommet under the jack, knocked it out and drained many litres of very smelly water revealing the roof ECU. needless to say nothing electrical connected with the boot area of the car worked! Had the Roof ECU stripped cleaned and repaired, fitted a replacement wiring loom to the boot components and ????? still no action! The search goes on for those missing Volts!
Same thing happened to mine in the recent storms. (We were away on holiday at the time). On our return I was horrified to see that you could literally stick goldfish in my boot and they'd have been super happy! Poked plug out so all of the water drained away quickly but it took a week of endless mopping with towels, drying electrics with a hairdryer and a big bag of cat litter (to soak up moisture) Thankfully, everything still works fine and I've taken to parking 'Charlie' facing down the slope instead of up. Just another adventure in the land of Copen ownership! ♀️