I really dont know how much will it be for the E6X, but maybe around $600-$800 extra. If not mistaken the HKS BOV (which I recomned) is an extra $180 as is the Haltech boost controller (which I would highly recomend). You will get accurate boost control and overboost protection. Definetely will need a new clutch (cant resist) and at least an EGT gauge. This will tell you if you are leaning out. If you have the money then a wideband O2 sensor would be great. I think AEM is coming out with an affordable wideband this year. Need to check it out.