I bought a set of Panhard Rods for 4/4. They were too short and did not fit into the frame. Had to order one that was for a +4. In other words: there is a different frame on a 4/4 and a +4 in 2005!
And, my documents show that the car is 1500 mm wide. Not 1550 mm as I measure.
That points to a different crosshead, rather than chassis. What size wheels and tyre do you have?