Avoid the less powerful engines, but the Stinger 3.3 V6 GT S is a belter: sweet handling, potent and much cheaper than an Audi S5 Sportbackread the full model review
GT-Line S additions include a ventilated front seats, heated rear seats, a powered tailgate, sunroof, LED headlights, a 360deg surround-view camera, wireless phone charging and a 15-speaker Harman Kardon sound system.
This diesel option is best avoided. It's pleasantly quick above 3500rpm, but is also far louder than is acceptable in a premium car. It's also inefficient in terms of CO2 next to its immediate rivals.