I own a 2008 Lexus IS250 and recently noticed what appears to be a stain or defect in the lower (seating surface) portion of my driver's seat. I have not spilled or put anything on the seat that would've caused this to appear. It almost looks like it may have been caused by perspiration from the back of my legs (while wearing shorts on a hot day) but the pattern isn't consistent with my legs as it is a rectangular shaped stain/imprint about 14" by 8" and is located more on the left side of the seat. Does anyone know what this might have been caused by? I tried to remove the stain with Connelly Hide Care/Cleaner but it didn't affect it at all. Any advice would be greatly appreciated.

 

Pictures please