Will this bolt straight on without any modification?

Yes. It uses the factory mounting points—no drilling, cutting, or bracket fabrication needed. Line it up and fasten it down.

Does the bulb come installed?

The assembly ships without a bulb installed. You'll need to source the correct bulb type for your vehicle separately and install it before use.

Is there a return window if it doesn't fit?

Test-fit before final installation. Once fastened permanently, fitment disputes are difficult to resolve. Verify mounting point alignment during initial assembly.