Yup, inside is just too small to incorporate anything else. It looks big from the outside but trust me, there isn't any extra or spare room for something like that.
Besides, there is more than just a projector in there hehe. Can;t forget about that turn signal
EVOs come with either halogen or HID projectors. The base RS EVO has the halogen versions where as the EVO 8's and 9's have them as HID. They are decent Stanley projectors but I'm not a fan of their double sides flares.