Can't find the fuel filter!

I assume your 2005 Buick LaCrosse is a carbon-copy of my 2006 Buick LaCrosse. IF this is the case, there is no fuel filter on these vehicles. There is just a screen on the fuel pump that shouldn't ever clog with decent fuel. If my car starts to hesitate under light-to-medium throttle, I simply dump in a can of "Sea Foam" fuel system cleaner and the problem goes away.

I have a 2002 Lesabre but suspect it is in the same vicinity. Look under the car, drivers side under the passenger door towards the middle of the car.