Mine's been doing good. Received in October. Works fine, thanks. Operates while driving. I programmed it to "not" flash red (brake) lights while in "drive", so I don't get a ticket from the police here in TX. You can program it to "not" flash any lights while in drive, if I recall. You can program the unit to "not" flash the headlights at all, if I remember right. Headlamps do not flash when driving at night. I can't see it voiding a warranty, as I cut no wires, but YMMV.
Best to all,
John, KF5ZMD