I'm at 13,000 and I'm past the wear marks on the outside of all 4 of my Contis. Mine is a combination of excessive toe-in (factory alignments are usually done by crude asssembly procedures, number of bolt turns and such) and scrubbing them off during hard cornering on soft sidewalls.

If you do most of your cornering throttle-off and have more of a tendancy to understeer it COULD explain the wear, But I wouldn't trust a factory alignment as far as I could throw the guy using the rusty T-square.