Completed first step to tuning the valver, pipercross panel filter. I now have a few weeks to choose exhausts. I have came up with three systems-Scorpion system, mongoose system and was also looking at an OMP group N/A system.All around the same price and i will be de cating the car unless i buy the mongoose or omp which come as a de cat back system, scorpion is a cat back. which one would you choose and why??