I know this sounds bizzare but I had the same issue and it turned out to be the rear seats.
Did you fold down the rear seats recently?
If you did, check if they fully lodged back in. If it's not fully latched in, it produces that squeaky noise every time you go over a bump.
Unlatch it and give it a strong push back in. The red mark tab above the fold down latch should be NOT VISIBLE if it's fully locked in.
Hope this works for you as it did on mine.