A method for the measuring of symmetry when in particular repairing cars including the use of a measurement bar comprising in each end a laser head that can be swiveled around the length axis of the bar. The laser heads can emit light beams perpendicular to the length axis of the bar. The bar is on a straightening bench (on which the car is mounted) mounted perpendicular to the length axis of the car. When the laser heads are swiveled their beams construct parallel planes on each side of the car from which measures can be taken to the sides of the car in order to establish if symmetry exist or how great the necessary correction has to be.