I think all BMWs are enthusiasts cars. Having recently visited the factory in Munich and engaged in a few discussions, I can say that folks there are quite passionate about their company and products. The 128i is the best BMW I have ever owned, yet I installed a bunch of BMW Performance bits to tweak the sound and handling to my taste. My coil over suspension gives a great ride height, just low enough, but not slammed and absorbs most road imperfections while keeping the body nice and flat through corners.
To me, an enthusiast car is not about maximum horsepower, it is about handling, style (the one series is very unique in the US), and that little thrill you get when you drive. Here in Virginia, the reckless driving statutes are so agressive that you can lose your license for doing a nice little burnout, or chirping the back wheels through a corner. God forbid you let the back end come out in a corner or go over about 90 mph in view of a police officer. It is not enough to fine you, they want to make keeping your driver's license almost impossible for the average driver. So, it makes more sense to have a car that handles great at moderate speeds. Safety-wise, BMWs are second to none. I would not want to have a crash on our beltway at 60mph in a US or Asian engineered car.
That said, most exotic or true enthusiast cars are quite uncompromising. I love the look and feel of my Lotus Elise, and stock from the factory, it handles far better almost any car. With light weight, acceleration is under five seconds 0-60, all while getting over 30 mpg. But... At 102 degrees (next weekend's temperature in DC) it is almost undriveable, as the cockpit just gets too hot. I did not take it yesterday because I had a trunk full off food for a party, and the Lotus trunk is, well, heated, and very tiny. Yet, the car gives you a thrill, and brings out wondered whispered anytime someone walks by it and has even a remote interest in cars. My 128 will drive around with the AC on in extreme temps, carry three cute girls and their stuff to the beach, and still allows a view of a moonlit sky on the drive honpme. You just can't beat that!