i just got a radar detector and i know a little about them, just correct me if i'm wrong:

X band: bs, automatic opening door on a business

K band: real radar

KA band: real radar

Laser: your screwed

a friend told me a car nearby with the gps navigation that come in some cars can set lazer off too. anyone hear that?

not sure if this one is true some stupid person at my work told me: K band is radar behind you and KA band is radar coming from in front of you...
is there any truth in that?