The BMW 535i is available in GT and sedan forms. The GT is a fastback, and the sedan has a long, sloping roof and a stubby little trunk. Either car weighs over 4000lbs and has a 300HP turbocharged I6. Both are very poor choices for most EcoModders.
What is interesting is the GT, despite its less steep rear glass, has a higher drag coefficient: 0.31 to the sedan's 0.29. Additionally, the GT has a larger frontal area: 32ft² instead of 29ft². Predictably, the sedan has better highway fuel economy.
The GT looks like its rear glass is too steep for attached flow, which might explain that little vestigal trunklid at the rear. Still, you'd think it had better aero than the sedan behind the C-pillars. Either that's not the case, or the GT has more aerodynamic defects (besides its greater size) elsewhere on the car.