Can anybody who has fitted the b./f. relocation kit give me some feedbacks on this kit. As I understand the PE and the Spec-R kit come with a sealed air-box and as such you can only use (open) cone type of air-filter eg. HKS and amp; Blitz. Whereas the Ralliart kit can use the original box/panel filter or the open type. Do you guys who have such a kit fitted find any difference in performance?