"Potentially rookie question"...I've been searching for equal length headers for my 2015 WRX and it seems there are nearly none, or it says it's for an STI. Where can I find decently priced headers, or can I just get the STI ones? Are they the same fitment? Thanks
Then you should be looking at aftermarket catback exhausts.. not headers. STI is a completely different turbo setup, so the header isn't interchangeable with your WRX.. neither is the BRZ.
For what it's worth, ETS makes an afternarket ELH for your car.. although I don't think it's made for the stock location turbo, since it's part of a complete kit. ETS 2015-2016 Subaru WRX Turbo Kit