Classic car races always bring out the rare and beautiful race cars of yesteryear. And none more so then this Mercedes W25 Silver Arrow, listening to it carving it way thought the Klausenrennen back in 2013. This 8 cylinder supercharged engine produces 354 hp, which is still a lot of power for cars these days. But you would have had to have balls of steel to be trashing this car around the mountain roads and full throttle, no electronic aids, no four wheel drive, just buckets of skill. Just listen to the engine, what an awesome sound.