If I get lit up by an unmarked when I haven't been doing anything, I am not pulling over for it. There have been too many cases of robbers impersonating LEOs. I haven't been put to the test, however.
I was told if it happens you can drive to a public spot to pull over, where it's safe. I just think routine traffic stops should be done with marked cars. I understand the need for unmarked, but for everything? BULLSHIT!