Unthreaded Plastic Nut, Saab 90413589
These unthreaded nylon nuts are used to attach panels and trims onto coarsely threaded studs. The thread cuts into the nut when it is first attached and as a result they are often best replaced rather than reused.
These are a high quality aftermarket equivalent to the genuine Saab parts. Saab typically used this type of fastener for bumpers, under body shields and wheel arch linings.