If you want some catless headers, sit in the classifieds section and wait for a set of Technik Gen3s to pop up. Expect to pay close to $800. These are going to net better gains than anything out there right now.
If you need to go a little more budget, go BimmerBrakes. They are actually working on a set of replicas for the above mentioned, too.
If you need to keep cats in the car, go with Magnaflow. Small gains, but you'll stay legal.
Do not pay $1100 for AA headers.
Last edited by aggieE46; 10-18-2012 at 02:47 PM.