http://www.nhra.com/content/general.asp?articleid=2211&zoneid=60&navsource=rule%20revisions
Page 54 (2/06)
Exhaust System: Add to section, "Turbo applications, aftermarket header permitted – turbo must be located in engine compartment."
That's for NHRA, all stock classes, and just became legal for the 06 season. So for those of you that run in Stock, your car just got a lot quicker. Notice it doesn't say "stock location" right now. That may change in the next few months as the NHRA reviews on how far under index everybody ran last year.