I realize an ounce of prevention is worth a ton of cure, I realized that when my ignition started acting up ($70 v $700 or so, I believe was the ratio). This morning the pump was quiet so it may be temperature related and with cooler weather forcast I may have been granted a reprieve.

But I'm still wondering why there two pumps. Are they the same? If one dies would the other one keep the car running? At least they are easy to change, I've heard the submersable ones inside the fuel tank are very expensive to replace. Thats another vote for Mercedes for designing a maintainable car