About choice of luxury/performance sedans, there's a lot of speculation Audi has poorer build quality when the company is the hot marque, like right now, and Benz doesn't have enough personality for me, so I would go CTS-V because the amount of horsepower and options for that price is insane, and the Nurburgring stats don't lie
Corvette ZR1 engine is in the coupe and for $60k you instantly compete with basically any road car