I am still really amazed at the SL500 though. I was amazed it previously managing 150mph (previous VMAX). I suppose looking at the BHP/weight of the car it probably isn't so differnt to the S4 apart from most likely having less torque, but I somehow doubted a MB V8 of that age to still be producing the full beans.
Well ... the de-limited top speed is well over 155, 180-ish IIRC? So even if a few of the ponies had wandered off over the years, 160+ sounds OK (assuming a 'generous' speed limiter). Of course if it was running on V-Power that would help, too.