Hi all. I just wanted to add the situation I have been experiencing in the hopes of any help. So, here goes..
I have a 2009 Genesis 3.8 sedan. Bought it in 2013 with 65K miles on it and no reported accidents. When purchased, I did notice that the cover that goes over the spare tire had appeared to have gotten wet somehow because it was slightly warped, seemed like it was rained on at some point. Didn't think too much of it.
Now come late 2018/early 2019, my Genesis has been blowing light bulbs in the right front headlamp, left fog light, both front side marker lights, and blinkers at times randomly. I have replaced each of these items at least once in the last year. And I see condensation in the fog lights.
In the last few months, I went searching and found water in the spare tire well and dampness on the trunk carpet on the far left side nearest to the backseat panel. A couple inches or so of water builds up underneath by the spare tire depending on the most recent weather events. And at times the carpet is dry but there'll still be water down by the spare. I live in the north east so we get snow and salt on the roads. So I did see rust around the spare tire and on the OEM tools for changing the tire. I will gladly provide any pictures if anyone is interested. Please note, the car battery is also located in the trunk of the 3.8 sedan.
At least, with the detailed help of this thread and the threads for the Genesis Coupes, I can move forward with some wisdom concerning what to look for and how to reach a solution in this matter.
Thanks everyone!