Carrier/rack problems of the 2016 Lexus ES350

Thin windshield. Windshield must be extremely thin. I bought a certified Lexus oct 2016. Windshield cracked starting from left black border around windshield. Safelite replaced it. 6 days later, driving down the highway and it cracked in the same place starting from the black border. No rocks hit it. I have been driving 35 years and never replaced a windshield. Now 2 in 6 days. Something isn't right Lexus.

I have own two Lexus's a 2014 and 2016 and it appeared that the windshields are extremely thin because I have had rocks crack them on the interstate, on both of the different cars. I am certain that others have had this troubles as well. I was traveling on a major highway.