They aren't reliable like Japanese, and even Korean cars, but they are definitely not junk, especially if you like to drive a performance automobile. If you want junk look at your typical base GM car.
I've owned a lot of cars, and to this day the nicest car that I've ever owned, and that I still miss, was an MB E63 AMG.
Cost of ownership was also probably the highest of any car I've ever owned, even when spreading it out over the 7 years that I owned it, but you wanna play, you gotta pay.
To each his own.