Those Subaru Impreza coilovers that do not include pillowball mounts can be equipped in such a way for a couple of reasons. In some cases, it’s to save both the manufacturer and the end user some money. In other cases, the manufacturer has determined that there would be no benefit to pillowball mounts for that particular application. For instance, with an entry-level coilover kit, it wouldn’t be expected that the vehicle would be driven to its limits, and so pillowball mounts wouldn’t be necessary. Keep in mind that pillowball mounts are available separately, so you can add them at any time if you so choose.

Subaru Impreza Non-Pillow Ball Mount Coilovers Page 5