Turbo- Thanks for your input. As the gauge shows about a quarter tank, and there seems to be fuel remaining in the tank, I can't imagine that the sensor isn't working. As for the fuel pickup, I am trying to locate someone that has actually removed their inline fuel pump from the tank... so they could possibly tell me if there is a tube or something that could split... causing the fuel to spray out the side of it once the tank level drops below the split. This exact situation happened to me once in a Volvo that I used to drive. However, the Volvo's inline fuel pump was attached to a rubber tube that (I presume) deadened the noise that the the in-tank pump created... However, from the diagrams I have studied on the Lexus, it looks as though the pump is one unit that is directly connected to the low (front) end of the tank.
Thanks again for your suggestions!