This is one of the reasons why I threw in the towel and bought my own tire machine and wheel balancer.

When the tire stores DO use a torque wrench, they are only using it to make sure the lugs are tight enough that they don't fall off. They are not using it to tighten the bolts equally and do not tighten them in a pattern. Most of these people are only there for a paycheck.

Actually overtightening the lugs in and of itself should not warp rotors if done in steps and in a star pattern. It's still not good if for no other reason than it makes it somewhere between difficult and impossible to change the tire if you have a flat.

The short lug wrench is plenty long enough to tighten your lugs properly. In fact I don't bother with a torque wrench, that's what I use, but I tighten them evenly and in a star pattern. I've done this on every Benz I've ever had and it has never caused warped rotors.

I have finally come to the conclusion that a common cause of warped rotors is tire foam. It hits the rotors in spots, even in a trace amount will cause problems. I am going to cut a circle of cardboard and hold in place while I use the tire foam to prevent any of it from finding its way to the rotors.

Before I started doing my own tire work, I had found a tire store that had no problem letting me remove and replace the wheels myself. They jacked it up for me and I took it from there. I would rather do that than to sit in a stupid waiting room anyway.

Have a great day,