I noticed today that im starting to notice a very fine groove happen to my front left rotor only... Pads and Rotors and Shims on the car was replaced by Westside Lexus in Houston about 5k ago because of the squeaking TSB... I dont have any squeaking but the groove bothers me any idea's????

 

Don't worry about it. Nothing will happen.

 

What??? Grooves on rotors indicates a problem! Could be a small rock lodged in there but most likely they assembled the parts wrong, Get it Checked!

 

You honestly think a rock could withstand the force of the calipers squeezing together?

 

Rotors get f'd up in all sorts of ways that are totally normal. They are like quantum entities, they get messed up looking just by observing them.