2006 Lexus RX Hybrid electrical system problems

The vehicle surges at a steady speed. I am most aware of the surging at 35-45 miles per hour. This did not happen until the vehicle had approximately 8,000 miles on it. I have been told there is no repair available and the lexus is aware of this problem.

While driving a 2006 lexus 400h the engine, power steering, lights, everything! Just quit and the car had to be maneuvered off the road with no power what so ever. It was very dangerous. The car's inverter had failed. This car has been maintained and serviced by the dealer for its entire life and has had no indication of a problem prior to the failure. The new inverter costs $8300! We will probably sell the car for salvage as its way too much money and who knows what will go out next!