if you are looking for a car with power....you picked the wrong car....unless you got about 6grand to put into the motor.
as for what you should do to it....it all depends on what you are looking to get out of the car.
the P5's handle incredibly well, so i would suggest setting it up for Auto-X thats what i am in the process of doing with mine.
but they also look damn good as a DD show car...