Despite a price that puts the brawny CLA 45 AMG at roughly the equivalent of two V6 Mustangs, there's no way to get a new über German car any cheaper than the $47,450 suggested price.
Audi has S and RS to differentiate normal hi-po cars from the hyperactive meatballs. BMW sort of has this with IS and S. Mercedes, though, has AMG and Black Series (and AMG S, actually). I'd argue that an AMG is more like an RS, which makes a Black Series vehicle purely insane.
Therefore, buying a CLA 45 AMG is close to buying an RS or an M of another brand. At the $47,450 price-point, you're not getting much else new from Ze Germans at that level (an SLK55 starts at $68K and the 1M Coupe was $55K before markup). You could argue an 2013 Audi S4 is comparable, but it's slower with less power at around the same price.
If Teutonic tire-murdering is your game, then, the AWD CLA45 is your best value in the United States, offering AWD and a 2.0-liter turbocharged four-cylinder with 360 horsepower. That'll boost it to 60 mph in a reported 4.6 seconds (the S4 does it in 4.9). There's no manual transmission, sadly, but that's the only obvious shortcoming.
Inside, the smallest locally available AMG looks the part with carbon fiber, massive chunky switches, carbon fiber stuff everywhere and red touches.
This leaves you with three interesting choices for under $50K. You could get a base 135is for the compact, relatively lighter weight RWD with a stick. The larger, relatively tame Audi S4. Or this. DD/Track/Burn?