Nice progress as for the exhaust any chance you can remove some of the trunk floor and go into the trunk around the tank and come back down.
Not sure what tank your using but you can also consider using a mustang style tank that drops in from the top and give you plenty of extra space for exhaust.
You can see that the well in the trunk has been removed and the tank has been elevated up to make the trunk floor flat. Which also hides the tank and allows you
to place a crash bar across the rear frame rails to protect the tank at the back of the car.
