Flashed by the civilian police, measurement not correct

Hello, I was flashed today in a 50 ́ zone by the civilian police with a laser device. However, I suspect that the police did not work 100% properly. There were also no optimal conditions available (at night, rainy ), but this is not the problem. Result 80km/h I drove according to the police, 3km/h tolerance, 27km/h too fast, 60€ + 3points. Time 00:30 there was absolutely no traffic, was also on the move, but I am very sure that I did not risk 80km/h I was more surprised that the police measured from the car, one of them apparently sat in the passenger seat and, according to the statement from the open window, carried out the speed measurement (windows on and laser device in the hand and measured ). Can result from this procedure a correct result. I was on a 4 lane road ( 2 lanes on each side ), and the police were not standing on my side of the road but on the board. The other side of the road had to aim at my car with the laser device, so to speak. I also have my concerns about whether it is so correct. What should I do, make an objection or is it pointless? Would actually also pay, but I was really not 80km/h fast, about 70km/h it was on the speedometer and my speedometer is not defective.