So I am making a simple game. I want to put a gun on top of a car. I want to be able to control the angle of the gun. Basically it can go forward all the way so that it is parallel to the ground facing the direction the car is moving or it can point behind the car and any of the angles in between these positions.

I have something like the following right now but its not really working. Is there an better way to do this that I am not seeing?

#This will place the car
glPushMatrix()
glTranslatef(self.position.x,1.5,self.position.z)
glRotated(self.rotation, 0.0, 1.0, 0.0)
glScaled(0.5, 0.5, 0.5)
glCallList(self.model.gl_list)
glPopMatrix()

#This will place the gun on top
glPushMatrix()
glTranslatef(self.position.x,2.5,self.position.z)
glRotated(self.tube_angle, self.direction.z, 0.0, self.direction.x)
print self.direction.z
glRotated(45, self.position.z, 0.0, self.position.x)    
glScaled(1.0, 0.5, 1.0)
glCallList(self.tube.gl_list)
glPopMatrix()

This almost works. It moves the gun up and down. But when the car moves around, the angle of the gun changes. Not what I want.