Subaru WRX with STI Spoiler Installation | Measure Twice

For a Subaru WRX with STI spoiler installation, the work involves drilling through the trunk lid, sealing every hole against water intrusion, and bolting the wing down from the inside. The process differs between the VB (2022–2024) and VA (2015–2021) chassis, and following the right procedure for your generation is the difference between a clean install and a leaky one. If you have not picked a spoiler kit yet, our roundup of the best WRX STI wing options can help you find one that fits your chassis and budget.

What You Need Before Starting

The specific hardware and hole locations come with your spoiler kit, so the kit’s own template is the one to trust. In general, you will need a drill with a set of bits — 1/4 in is common for pilot holes — a hole saw or step bit for enlarging holes, adhesive sealant or foam gasket material, a ratchet or torque wrench, and a second person to help with alignment.

Most kits include a paper template. Align it carefully on the trunk, center it, and tape it in place. Several installation guides stress that misalignment at this stage is the most common and expensive mistake — once the holes are drilled, there is no moving them.

STI Spoiler Installation By Generation

2022–2024 WRX (VB Chassis)

The VB chassis uses a wing available with Series 1 or Series 2 hardware, and both share the same drilling pattern.

The drill can pass through a second layer of sheet metal near the weather stripping, so a microfiber cloth is used as a protective barrier there.

The full workflow: remove the trunk liner clips, mark and drill pilot holes, enlarge each hole to the kit-specified size, apply foam adhesive or gasket material around the base, set the spoiler in position, and bolt it from inside the trunk using the supplied washers and nuts. Hand-tighten first, check the alignment, then tighten evenly.

2015–2021 WRX (VA Chassis)

The spoiler mounts with three bolts per side, and one kit requires an additional 5/8 in hole on one side — another reason to treat the kit’s own template as the final authority.

The same general sequence applies: remove the trunk liner, drill pilot holes, enlarge to size, apply sealant, set the spoiler, and bolt from inside. After the hardware is tightened, reinstall the trunk trim and clips. A final check should confirm the spoiler sits evenly and the trunk opens and closes without binding.

Common Mistakes — And How To Avoid Them

Wrong hole size, misaligned template, over-tightening, and water intrusion show up repeatedly across installation guides. An incorrect drill size can prevent the washer from seating or weaken the trunk lid. Over-tightening the hardware can crack the spoiler or damage the paint beneath. Skipping or skimping on sealant guarantees a wet trunk after the first car wash.

Compatibility is another hidden trap: a VB wing is not a direct fit on a VA trunk without the correct template and mounting hardware. Verify that your spoiler kit matches your generation before you drill anything. The Noble STI spoiler install guide for the 2022+ WRX demonstrates the hardware differences between Series 1 and Series 2 and shows the exact drilling and stud setup for the VB chassis.

FAQs

Do I have to drill holes in my trunk lid?

Yes. An STI spoiler mounts using bolts that pass through the trunk lid and are secured with nuts from inside the trunk cavity. There is no stick-on alternative that provides the same structural security. The holes are covered by the spoiler base and sealed to prevent leaks.

Can I install an STI spoiler by myself?

It is possible but not recommended. The wing is large and awkward to hold in position while you reach inside the trunk to start the nuts. A helper makes the job faster and dramatically reduces the chance of scratching the paint or drilling misaligned holes.

Will drilling the trunk void my warranty?

Drilling is a permanent modification to the trunk panel, and that panel’s warranty coverage may be affected. Other warranty coverage on the vehicle is not automatically voided. If this concerns you, check with your dealer before starting the install.