u havent reported if the onset of pain was exactly AFTER the accident, or the anterior chest pain was developed during this time interval (10 months) for no apparent reason....I would agree with Physiobob about the supplements u could make on your regime and i will remind you that CERVICAL DISCS has a huge potential of referring pain on anterior chest pain....Check Slipman articles on cervical discography on pubmed...You should use Mckenzie principles (i am not sure that only retraction/extension will do the job) but beware to make proper mechanical diagnosis (dont know if you are familiar with the method) because other forces than retraction can be indicated (for example lateral flexion).
And my advise on "nerve mobilisation" techniques as you have mentioned: its just a waste of time...Many times these maneuvres elicit false-positive results (nerve tissue is MECHANOSENSITIVE so DONT IRRITATE it by any means!!!) and despite some "early" positive results u may gain, u will rarely get positive outcomes counting only on these (as i often observed on practice)