I drive a 99 Pontiac grand am, sometimes my
car will already want to accelerate before I
even put my car in drive. The rpm side will
shoot all the way up. Sometimes when I’m
driving I don’t have to press the gas at all and
it will still accelerate by itself. It doesn’t
happen every-time I start my car but every
now and again sometimes back to back for a
few days but not every-time I start my car.
I've replaced enough motor mounts in race cars to believe that that's your problem: broken motor mount. This can happen on its own just through age, or it happens often when the car has been treated rough or has been in an accident.