I don't understand the reluctance to run exhaust under the rear? We have done a couple of cars this way and both work just like any other exhaust. You can't see it from the rear, and it doesn't hit the ground, so where's the problem? Just cause it's always gone over the rear does not necessarily mean it always has to go there.
You could see it on mine and for instance adjusting your rear coilovers would require the exhaust to be removed so you could take the pressure off the springs and let the rear end droop. Hey it's a killer car just purely stating my 8 cents worth on why I don't want it that way.
heres vinnys car, pipes clear bags by 1 inch, hes got 3-4k miles on the car with no issues, its full 3 inch pipe, 2 dimples are made for the casting gusetts on the 12 bolt.and vinny drives his car as hard as anyone