Got the car inspected yesterday as planned and they confirmed that the seal had gone at the top of the red boost hose. I pointed out to them the info regarding the improved hose and they agreed to renew it as well due to the repeat history of the fault. For your info the part numbers of the new parts are :
11617812274 - charge air line ( flexi red hose)
11618506786 - top seal ( for flexi red hose )
If you clicky this :
http://bmwfans.info/parts/catalog/E9..._air_duct_agr/
you will see the parts in question Items 1 & 2
heres hoping it is cured this time !
And while is was there i questioned them if i could claim warranty of the door window seal high gloss trims and they have agreed to replace under warranty . Result
some good has finally come in the end for all the hastle