Will this mount at the factory towing mirror brackets without modifications?

This mirror uses factory mounting points — no drilling or bracket fabrication required. Bolt it directly to existing holes.

Does the heater work independently of the power windows?

The heating element operates on the same power circuit as the mirror motor. When you have electrical power to the mirror, the heater functions automatically.

Is this mirror stable at highway speeds with a loaded trailer?

Factory-designed towing mirrors are engineered for trailer loads at highway speeds. This assembly matches OEM specifications for stability and vibration control.