Soundguy,
I have used them for years while snowplowing and recently on an airport project. All of them are the magnetic base and cig lighter power cord. I run them through the passenger side door weather stripping with no ill effect.
The cheapo rotators (wolo and other "house" brands) work pretty well, but they don't last long, especially bouncing around in the truck tool box. I bought a Wolo brand LED that has lasted the longest so far, but has less light output and is barely even visible during the day. That was a problem on the airport, as we were required to have flashing beacons on all vehciles while onsight. Mine was on, but even when looking directly at it from a reasonable distance, it was barely noticable. Night time use is acceptable, but not brillant.
The good thing about all the LED lights is that it does not draw much power. Had a couple conventional rotators that burnt out my power plug/ cig lighter as the aged.
All of these would be very easy to adapt to a 7 pin trailer plug. I've done that with additional back up lights to stakes for the stake pockets in my truck. That way I could install/remove them quickly for plowing and not have them mounted permantently.
