Does this mirror use factory mounting holes, or do I need to drill?

Factory mounting points line up directly — no drilling. Bolt straight to existing holes on the right side of the truck.

How does the LED amber signal wire into my truck?

The signal assembly connects to your factory turn signal circuit. Routing and connector type depend on your specific truck's wiring — have your vehicle's service manual handy before starting.

Is this mirror stable at highway speeds?

Manual mirrors are rigid once positioned. Vibration and wind buffeting depend on how securely it's mounted and the condition of fasteners — tighten all bolts firmly and verify stability before highway driving.