How to install a boot spoiler on a BMW sedan

Step-by-step instructions

1. Clean and test-fit

1. Thoroughly wash the boot lid and dry it with a microfiber cloth.
2. Place the spoiler on the boot lid without adhesive.
3. Centre it carefully so the gaps to the left and right edges of the lid are equal.
4. Apply masking-tape marks along the spoiler edges to record its exact position.

2. Prepare the bonding surfaces

Degrease both the spoiler's mating face and the marked area of the boot lid. If using automotive double-sided tape, apply adhesion promoter if recommended by the tape manufacturer, then run 8–10 mm tape along the full inner length of the spoiler. Fold 3–5 cm of backing outward at each end so it can be removed after positioning.

Polyurethane adhesive sealant can be used instead of tape. Apply it to the spoiler in accordance with its product instructions and do not use tape primer with the sealant.

3. Position and secure the spoiler

1. Place the spoiler on the boot lid using the masking-tape marks for alignment.
2. For double-sided tape, pull the exposed backing tabs until the protective film is completely removed.
3. Press firmly and evenly along the full length of the spoiler.
4. Warm the taped joint moderately with a heat gun or hair dryer to activate the adhesive without overheating the paint or spoiler.
5. Hold the spoiler down with taut strips of masking tape running across it and onto the boot lid.

4. Allow the adhesive to cure

Leave the securing tape in place for the adhesive manufacturer's full curing period—typically 24–72 hours. For at least the first 24 hours, do not use a pressure washer and avoid high speeds. Once cured, remove the masking tape and check that the spoiler is secure along its entire length.

All photographs are illustrative. Follow the adhesive manufacturer's temperature, preparation and curing requirements.