I had the a similar issue in a similar car, looked into shims etc. pulled the motor because I thought it was bad,and said to myself, self you should video this, so I put the starter motor back in, making sure to push the motor towards the top of the engine as far as possible.
Not sure what happened the first time but reinstall and starter motor sounds great and has been trouble free for 3 years since. Could be a bad starter motor, but mine was slow and sounded bad, and now all is good, hope this helps.