Hi Francisco i'm a key in south africa. the one way i do it is to take out the back seat, both bottom and back rest if possible. if not then just bottom. then i rig a 4' slider to two cubes strap down ,you now have the option of sitting under the slider and creating a move left and right or just locking it off. i use the dragon grips slider.
the other option is to run a strap under the camera base though the doors strap tight till you feel the tension is right. you still have the option to pan and tilt