In the rear, the rubber component between the upper mount and the spring must be trimmed to the TEIN spring's inner diameter of 70 mm. Otherwise the spring cannot fit securely onto the upper mount. It can obstruct ride height drop and/or it may shift while driving, causing noise.
It is advisable to use a large utility knife that you can apply force to, with a new blade. It works best if you first cut notches marking a 70 mm diameter circle, then cut away the edge. Please work safely.