1992 Audi Quattro Where is the fuel Pump?

When I go to start my car, there is no gas getting to the engine. We checked the fuel filter, that's fine and my mechanic friend said it was the fuel pump. But when we went to take the fuel pump off (in the trunk) to get the part number, there is no fuel pump. We can't find it. The Audi dealership explained where it was, but there is no pump, no wires. I'm sure their could be that freakish possibility that it fell into the gas tank, but then the wires would still be hanging out. I drove home fine, but when I went to go to the store, that's when the car wouldn't start. It's been 3 weeks and I need my car! Any ideas?