Hey guys.. the exhaust can take some adjustment, as we have discussed. The best method (not saying anyone hasn't done this.. but I conferred with my service manager) is to loosen everything, and jacking at the y-pipe (hard!) get the clearance necessary to clear the crossmember.
This will take loosening the bolts at the catalytic converter brace which hooks to the transmission. This is a slotted brace, and can give you the 1/4" needed to clear everything.
You should not have to heat anything up to make clearance..
I have a 350Z on the rack, I shot a quick picture to show the location of the brace and the bolts I speak of:
