Hello,
Bought this vehicle not long ago.
In the trunk I found a plastic piece, with the above part number, and also an >ABS< marking on it.
Could not find the location of it, even though it is not small, around 12in x 6in x 4in, but irregular shape.
Any ideas?

 

Looks like a cover for the front of the seat track..left hand side? Check the rear seats where the track attaches to the floor.

 

Yes, you were right.
The cover for the seat tracks in the second row, in between the left seat and middle seat. Went back in its place very easily.
Thank you very much.