'02 325xit...I recently replaced my right front strut/shock because the perch that the spring sits on rusted off! Actually, due to rust it slipped down the strut, allowing the spring to extend and thereby lowering that corner of the car. Eventually, what was left of the spring perch twisted and its edge cut into the inner sidewall of the tire. Perfectly good tire was ruined.
At any rate....I was able to get an OEM Sachs Boge strut from PartsGeek.com, right front Part number 31 31 6 751 132, for something over $200. SDealer wanted $297.