If they go out and still come back on, you could have an auto lamp functionality issue, or a concern with the headlight switch and wiring connector. Testing hands on is required to see what is happening - diagnostic equipment will be helpful and needed also.
RepairPal Certified shops can diagnose and repair your 2007 Lexus LS460. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.