Hello, Since car door knocked you in the elbow and you are saying pain in the shoulder with weird sounds. Limb sudden extension like your case may cause dislocation of shoulder joints which can produce some clicking sounds. In your case if it is a due to dislocation injury it is mild since the arm bone (humerus) is possibly not out of the shoulder girdle (scapula). There are some important nerves to arm are passing which when compressed can also cause numbness. You need to get a X-ray after consulting your orthopaedician for further course of treatment if it is a shoulder dislocation. Bye