After a few hurdles and hiccups with my '04 mk1 BA Auto Sedan, RDP have managed to successfully tune it to 404rwhp. Mods to achieve this are as follows: Necessary Mods: 42lb Bosch Green Tops Nizpro Springs Redback Twin 2.5" Quad Exhaust System 3.75" Balistic 100cpi Cat into single 3.5" mild steel to a twin 2.5" collector to match the Redback Sytsem (pics can be found here) K&N Filter and of course Xcal2 with custom tune Mods to make it Easier/Safer: 4" Mild Steel Dump 8psi Actuator Spring HD