heh yeah the Uniden's rear laser has never been great.
I remember doing a laser jammer test sometime back. When driving back towards the start of the course, I had people shooting me in the rear since I have rear jammers. To see a RD's best case scenario for rear laser detection, I mounted my RD up high by my RVM so my headrests wouldn't be blocking the signal and I even put my top down to make sure that nothing would be blocking the laser signal. Since I was doing multiple passes, I tried several different detector like the V1, Redline, and I think one of the Max's. All of them struggled to detect from the rear when my rear plate was being targeted, even in that virtually ideal detection scenario. The V1 did the best of course, but even that detector didn't go off until I drove away from the lidar gun a bit.
So rear laser detection tests are fun to do just to see how the differences between detectors, but in practice it has little no to impact in helping you avoid tickets..