Now have 4000 miles on my Sonata, 2000 miles from home, and at least 100 miles from the nearest Hyundai dealer. Notice my left front rotor is scored for about an inch in the center of the outboard side of the rotor. Soft part of rotor? hard part in disc pad? All other rotors nice and smoothe!!
Something probably got caught between the rotor and the brake pad. It's unusual, because there is very little clearance for anything to get in there.
Unless you feel a pulse in your brake pedal, it's harmless.
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