With your wide open autobahns encouraging high engine speeds, be aware of modifying the tail pipe angles and shortening the distance they protrude. Due to the sugar-scoop decklid, there is a big swirl of air that follows the Pantera and plasters itself against the rear body. That air-action is how the stock a/c intake works.
During a sanctioned open road race here in Nevada (U.S.) some years ago, one owner with a 500 horsepower GT-5 Pantera (changed to angled tail pipe tips & modified exhausts), ran the 92 mile long course at an average speed of 150+ mph (bursts up to 175). at the finish, he found his plastic tail light lenses MELTED from his modified exhaust tip heat just below.
He had shortened the exhaust tip protrusions & tucked them up close to the split bumpers for a 'cleaner' look. NOT a good choice, as it turned out.... I lost the photos he took on an old computer- sorry.