Hello from Germany. I'm a 6 time BMW owner 3 of which have been M cars. Currently I drive a US Spec 2007 Z4 M Roadster. Current upgrades are Eisenmann Race Exhaust and RPI Ram Air Intake. I'm currently talking with Roman about ESS tuning. I'm here looking for some information and tips on upgrading my car. I guess the first question is: Headers, euro headers or something aftermarket (Super Sprint)? I'm interested in your opinions.