Lower back and hip pain post MVA

I have been seeing a client since March this yr. He was involved in an MVA Oct 2011.
Initially he went to hospital with right anterior rib cage pain and lower back pain but was discharged the next day as x-rays of back and pelvis were clear.

Initially he presented with strong hip joint symptoms on the left side, including a feeling of pinching when walking and corresponding Trendelenberg sign. The lumbar spine was also affected, particularly restricted into extension (hinging at L5). He initially had tightness and joint restriction of the left upper lumbar area L1-3.

He has made progress over time however symptoms are still fluctuating.

Currently: he has very good ROM of the left hip with only mild pain at the end range of flexion, combined flexion/internal rotation/adduction and also notices symptoms at 1/2 range of flexion/external rotation/abduction. There is some increased tone of left hip flexors, however this is much better than previously and I don't think this is the key restriction at the moment.

Main complaints:
-The hip joint locks, particularly after prolonged sitting (the amount of time to agg symptoms seems to vary).
-Walking (for 20 min or more) causes an ache which takes about the same amount of time to ease. He is not keen to walk as he is afraid of aggravating symptoms.
-Standing or seated (or even lying) right rotation aggravates the left hip joint
-Lying supine produces pins and needles in the left foot after about 10 min

The lower back symptoms are progressing well. Today I treated L4 and L5 into extension, both joints replicated hip joint pain and eased after treatment. However, he still had some mild symptoms though range on testing after this.

I have been treating the hip with traction mobs in flexion (caudad and lateral) and this helps too, after doing the lumbar mobs.

Today I investigated the right upper ribcage as this was the first time pt has told me about this area being involved in the initial injury. I thought maybe it could be involved with a diagonal tension pattern to his left hip? Especially as he gets pain with right rotation. Anyway, there was some significant muscle spasm around the abdominal attachments of the lower ribs. Pt was not keen on me working on this area as it hadn't been bothering him since the injury and palpation of it replicated initial injury symptoms (but only locally). We did achieve some release of this area but there is more to go, if he can cope with that. This work hasn't had any immediate effect on the hip, but I'm hoping that maybe it will.

I am just a bit concerned about the fluctuation of symptoms. At one point I thought he was looking really close to discharge but now has gone back a bit and hasn't changed much with ADLs etc. And not quite sure about how much the lower back and hip are contributing to current symptoms. I think the lower back is a big driver, as palpation can replicate symptoms but I'm not sure what else I am missing. Any suggestions?