Will this diffuser scrape on driveway approaches or steep inclines?

The three pieces mount along the rear lower fascia. Check your vehicle's stock ground clearance at the rear bumper line before installation — if your current setup clears standard driveways, this diffuser follows the same plane. Verify fitment at your lowest approach angle.

Is this functional downforce or purely cosmetic?

The Ergo design adds visual presence and rear-end definition. FRP diffusers of this style provide minimal aerodynamic effect at street speeds; the primary benefit is aesthetic depth and profile enhancement rather than measurable downforce.

What prep work is required before painting?

Sand the surface and apply your chosen automotive finish following the paint manufacturer's instructions. No special prep beyond standard surface preparation — treat it like any primed panel.