Do these mount at the factory mirror points?

Yes — these mount at OEM locations with no drilling or frame modification needed. Direct swap onto existing hardware.

How do I wire the heater function?

Wiring harness and connection points are included with the assembly. Route wires through the door panel to your truck's electrical system — refer to your vehicle's service manual for proper circuit integration and fuse placement.

Will these stay stable at highway speeds while towing?

Yes — the towing-width design and factory mount architecture maintain mirror stability under load and wind conditions typical of trailer hauling.