Ok, lets do some math. I'm not sure if you are talking about the SL 500 Roadster or the SL 55 AMG so I'll list both.

SL 55 AMG
MSRP $124,020.00*
Engine AMG-built supercharged 5.5L 24-valve V-8 engine
Net Power 493 hp @ 6,100 rpm
Net Torque 516 lb-ft @ 2,750 - 4,000 rpm
Performance
Acceleration1 0-60 mph in 4.5 seconds
Fuel economy
EPA estimate2 14 mpg
Highway estimate3 20 mpg
Emission certification TBA


SL500 Roadster
5.0L 24-valve V-8 engine
302 hp @ 5,600 rpm
339 lb-ft @ 2,700 - 4,250 rpm
0-60 mph in 6.1 seconds
MSRP: $92,020.00*

Now lets compare that to the viper which can be found at most Dodge Dealerships in the US.

500 horsepower
525 lb-ft of torque
505 cubic inches of displacement
Acceleration1 0-60 mph in 4.0 seconds
Standing 1/4 Mile (stock) 12.1@119.3 MPH
Lateral Acc. 1.02G (Lets see the benz do this)

Best of all, it's made in the USA!!!!