The rear popping noise sounds like a loose shock absorber mount bolt or a structure piece got unwelded/unriveted . Nice car but that noise would drive me nuts.
The Genesis vehicles are beautiful. I have seen them in person and sat in them. They are comfortable, full of premium features, and have the best warranty out there…along with Hyundai and Kia. I have been driving Jaguars for years. Believe me, these are premium quality vehicles.