Already one of our most performance-tuned models, the BMW M4 has been heavily upgraded for 2015, and it has already been drawing some rave reviews in its updated form. Let's have a look at one such review.
Isn't that impressive? And perhaps even more excitingly, this new M4 is also available in a convertible form as well. Equally performance-oriented, the convertible M4 features massive air-intakes on the front, a forward-sloping stance, and of…