2003 BMW X5 3.0 slow to crank

This car has 60,000 miles on it and has been regularly serviced by a BMW dealer. Over the last few weeks, it has been slow to crank. Sometimes nearly 15 seconds turning the key. It continues to happen even when the car has been driven for a while. Sometimes it will start quickly, but more often it is slow to crank. I took it in and was told it was either the fuel filter or the fuel pump. I have had both replaced and it is not different. Once I pull out of the gargage there is a heavy gasoline odor as well. Any ideas on what the next step should be?