Take off the bumper and sell it to me. This will increase your gas mileage by 8mpg's. If you were to give me the lift and the tires with it you will be in league with the prius.
Otherwise I bet if you were to change plugs, wires, coils and timing it would help a good bit. Check for leaking seals under the car the make sure the valve cover isnt leaking any oil.
Those tires are heavy and perhaps regearing would help? Otherwise you don't have many options. Hopefully that isn't a daily driver. MPG is the only reason i haven't lifted, armored, and mega rubbered (it's my daily driver).
You live in Bham? When i do lift it in the spring we will have to meet up somewhere and do a little wheeling