Quick answer

If you want a subtle, lower-cost rear accent, go with the Genuine Acura TLX Rear Diffuser. For a more aggressive, full-perimeter look that includes front and rear coverage, the Underbody Spoiler set is the better investment.

What each part does differently

The Genuine Acura Rear Diffuser is a single-piece black plastic trim that attaches below the rear bumper. It adds a sporty visual finish without changing the car’s overall stance. The Underbody Spoilers—available as separate front and rear pieces—wrap around the lower edge of the car, giving the TLX a lower, more planted appearance from every angle.

Both parts are factory-designed for all 2021+ TLX variants, including RHD and international models, so fitment is identical. The real difference is coverage and visual impact.

Budget and installation trade-offs

The Rear Diffuser is the more affordable entry point at roughly half the price of a single underbody spoiler. It installs as a standalone piece, making it a quick weekend project. The Underbody Spoiler set costs more overall, but you get two pieces that can be installed together or separately. If you eventually want both front and rear coverage, buying the spoiler set is more cost-effective than mixing a diffuser with one spoiler.

Trade-offs at a glance

  • Rear Diffuser only: Adds a single black rear accent. Lowest cost, easiest install. No front coverage.
  • Front Underbody Spoiler only: Adds a lower front lip look. Can be painted to match. Leaves the rear unchanged. You can start with the front spoiler and add the rear later if you want full coverage.
  • Full Underbody Spoiler set (front + rear): Wraps the entire lower perimeter. More dramatic visual change. Higher upfront cost but better value than mixing a diffuser with one spoiler. If you plan to upgrade both ends, buy the set from the start.

Product facts at a glance

  • Genuine Acura 2021+ TLX Rear Diffuser, Black: Fits all 2021+ Acura TLX variants including RHD and international models. Factory part number 08F03-TGV-200B. You get a direct bolt-on rear accent with no guesswork, backed by OEM quality.

    Genuine Acura 2021+ TLX Rear Diffuser, Black

    Genuine Acura 2021+ TLX Rear Diffuser, Black

  • Genuine Acura 2021+ TLX Underbody Spoiler, Front: Factory underbody spoiler for the front of the 2021+ TLX; available in multiple color options. Part numbers 08F01-TGV-210/220/230/240. Color-matched front spoilers let you match your TLX’s paint for a seamless, factory-integrated look.

    Genuine Acura 2021+ TLX Underbody Spoiler, Front

    Genuine Acura 2021+ TLX Underbody Spoiler, Front

  • Genuine Acura 2021+ TLX Underbody Spoiler, Rear: Factory underbody spoiler for the rear of the 2021+ TLX; also available in multiple color options. Part numbers 08F03-TGV-210/220/230/240. Pairing the front and rear underbody spoilers creates a balanced, aggressive stance without aftermarket guesswork.

Which upgrade fits your goals?

Best for

  • Drivers who want a subtle rear accent without changing the front look
  • Owners planning a full lower-body aero package and prefer a cohesive, color-matched appearance

Not ideal for

  • Anyone seeking a dramatic visual change on a tight budget (start with the diffuser)
  • Drivers who want front-only coverage and plan to skip the rear entirely (the diffuser adds rear presence without requiring a front spoiler)