I noticed on your (tempting) 700+ kit for the LSA '09-'12 CTS-V, it appears to use the factory headers (super-restrictive) and exhaust. Have you tuned a car with the Corsa exhaust and AR headers you offer on your site, and if so, what sort of power gains were there-or could there be, and do you offer that as a package upgrade option with the 700+ kit?