Yushido

Hi all im new so be gentle... i have had my 2010 A6 allroad for nearly 4 years and still love it but inhave been changing suspension components since ive owned it. Its had two lower front control arms on driver side( lemforder not cheap stuff) and one on near side. Its had the upper inner and outer control arms and now needs another one of tose they seem to be very hard on cntrol arms and links. main reason for post is ive had to change both rear airbags fitted aerosus ones and sorted the sink over night but i had a knocking noise from rear nearside and thought it was the top rear strut mount so i had this changed but noise still there only hear it on downward stroke so think the adaptive damper is goosed. On investigation i have had to have a stiff brandy to revive myself after seeing the cost of replacement. Is there anyone who refurbishes the rear shocks at a reasonable cost? On another note would anyone recommend changing all the bushes for PU bushes and have any experince of them? Rear subframe and control arms etc? chris