The only downside to replicating the noise of a W204 C63 AMG is the fact that you're "up against" a naturally aspirated 6,2-liter V8.
It's usually these types of power units that have the "X-Factor", and not these newer and more efficient turbocharged engines - which are obviously better overall, however, as it often is the case, not better sounding.
So can you really make a 204 PS 4-cylinder Mercedes-Benz C-Class sound similar to an AMG-powered one? Even one which was good for 487 PS when equipped with the Performance Package Plus?
As far as we can tell, the answer is "sort of". The fact that the C250 lacks power is more than just obvious once the car starts revving its engine beyond a certain rpm marker. However, as long as you leave it at idle, it's a little harder to say that you're definitely dealing with a car that's just posing as an AMG instead of the real thing.
However, C-Class owners who want more in terms of their car's acoustic footprint might want to check out this exhaust update from Armytrix.
Also, the reason why you're hearing an unnatural high-pitched whistle in there is because the W204 C250 was turbocharged. Good for fuel economy and performance, bad for tuning your exhaust system.