Yep, just go to your kitchen, bring a hammer, bash your microwave door out, then mount the thing on your bumper facing backwards. Next you'll need a big inverter. When a cop starts following you, just kick that sucker on and nuke the radar gun :-D No, in all seriousness I do know that my state has gone to mostly Lidar, its also harder to question lidar because it was a laser pointed directly at your car, not a radar which could've picked up the car next to you.. Now, to interfere with Lidar... I would imagine all you'd have to do is find the wavelength that lidar uses and emit a lot of that wavelength... simple overload of the sensor should do the trick.
Also this is all in fun, do NOT ever operate a microwave open, the first thing it will do is take out your eyesight as your eyes resonate near microwave frequencies.. Then life starts to really suck.