Will this scrape on driveway inclines or speed bumps?

The diffuser extends downward from the factory bumper line. Check your vehicle's current rear bumper clearance on a driveway slope before installation — if factory trim clears, this panel will too. Mounting height depends on how you position it relative to existing bumper attachment points.

Is this functional downforce or cosmetic only?

This is styling-focused. A diffuser generates minor aerodynamic effects at very high speeds; at street and moderate track speeds, the visual impact outweighs measurable downforce. Think of it as Twins aggressive aesthetics with real carbon fiber construction, not a race-spec aero component.

What prep and finish should I apply?

Carbon fiber arrives raw and unfinished. Sand and prep the surface before applying your chosen clear coat or paint system. A UV-protective clear coat will preserve the weave pattern and protect against oxidation — standard automotive clear works well and is your best insurance against long-term gloss fade.