I got my first experience when I bought an 2006 IS250. In 2014 (the car was now 8 years old) I got a recall letter that one of the windshield wiper bolts may not have been torqued to spec at the factory. Not kidding. I ignored this letter, as I was sure this was just some trick to get me to visit the dealership. After 2 months I got another letter telling me that this issue was not yet resolved, urging me to go get the free repair. I did.
In 2015 I had a complaint that the parcel shelf would make a creaking noise if the car was parked in the sun for a while. They replaced the parcel shelf under warranty (this was a 9 year old car at the time!).
In 2016 I got a recall that the fuel filter may not have been properly installed 10 years prior at the factory, so I got a free repair again.
Finally in 2018 (12 year old car), they replaced the passenger airbags free of charge, as there may be something wrong with those.
Their attention to quality is insane. In the 10+ years that I have owned Lexus cars (first an IS250, now an IS-F), I've had zero defects (that I had to pay for). That said, I do always bring in the car for service at dealership at the recommended intervals. Proper maintenance gets you a long way.