Rear parking light bulb

From what you're saying, it does seem like a failure of "Light Failure Sensor" because two parking light-bulbs were blown for the first time in the life of my car and it may have been associated with some type of over-voltage shock that blew them out. The same over-voltage shock may have blown the LFS, I'm guessing. By saying "left front corner of luggage compartment" do you mean by the secondary gas tank door release tab inside the trunk above (or below) the driver side rear wheel's wheel-well hump? Does Lexus have a part number of the LFS and what does it look like and what's the estimated price?