Rear swaybar

It depends on the exact shape of the swaybar. Whoever told you that it can't be done might have meant that the exhaust would block the installation of the swaybar. It might be possible to remove the exhaust to install the swaybar and then replace the exhaust. Or, if they cross paths, ( or occupy the same space) it might be possible to route the exhaust around (under) the swaybar. How about dual side-pipes exiting in front of the rear wheels?

(Fewer bends means less restriction)