If you don't want to pay for genuine MB rotors, which from my experience are not much more expensive than aftermarket brands, I recommend ATE coated rotors. The coating, as on the genuine MB rotors, is a light gray primer which protects the non-contact surfaces from rusting.

As mentioned a stuck caliper can cause overheating resulting in rotor warping. You may want to remove the front wheels and check that the calipers release completely, and that the caliper pistons move easily.

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Fred Hoelzle