Yes, tinting is an aftermarket choice. And then unless the tinter has any idea of how the car is put together, water flowing from the inside of the window to the trunk is pretty unexpected. Or at least any damage associated with it. I have a feeling placing the amp in the trunk was for weight and balance a lot like placing the battery there. I hope all new owners get wind of this issue so the damage can be avoided. I am so glad I am on this forum learning all of this. I think the best idea is to wrap the amp and tape seal it. Then seal tape the gaps under the window and use absorbent materials in the flow areas to catch any leaks.