I had my alignment done at Firestone. I got the lifetime alignment for $199. Not sure if they zeroed out the SAS but I have all the BMW software to do it as needed. I believe most if not all E53s just require a steeringnl wheel lock to lock and back to center to auto align the SAS. I have used that procedure for many friends who have had the SAS calibration error on their E53s including having the DSC light lit up only on the cluster...

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02 Imola on Black Dinan S2 4.6iS
00 RoyalRot on Sand/Black 740i Short Sport