A replacement BMW sway bar link for most models of this automobile are straight with no bends in it. They can be either short or long also but no matter how it appears, its function is to secure the sway bar from the frame to the cars suspension to help keep all four wheels on the road at all time independent of the road conditions your BMW might encounter. This suspension part has several different types of ways it is connected. The end of the sway bar (or stabilizer) link can be fitted with a ball joint that has a stud protruding from it for a secure fit. There are other ends of a BMW sway bar link that look like a hole that are lined with a polymer gourmet in which a bolt or stud can be place thru it for a secure placement. Your link could have one of each type of link or both of them to be the same. A stabilizer bar link should be replaced when either the polymer gourmet has become worn, cracked or the ball joint has too much play in it. You can observe this by asking the technician that is replacing the sway bar link on your BMW for the old and worn out parts. This is your right to ask for this or any other part taken off of your vehicle because you own all of the parts on your car. A worn out stabilizer link will adversely affect the handling and cornering ability of your BMW as you travel down the road. When driving, if the handling seems to be sluggish or not responding as it did when newer, then an inspection of these important suspension parts is recommended.