My share of input, which contains some physics stuff:
I think that motherson did more than just speeding. He was weaving
in and out of the traffic like james bond. You ppl should know,
even if your speed is damn fast, if the angle of your wheels and
the curb is not steep enough, the wheel will only adjust itself to
the front direction. To mount curb, that means that the angle which
the wheels meet the curb is MORE than a certain critical
angle.
If you still remb secondary physics, in refraction, if the light
strikes a glass block at less than a critical angle, it will get
reflected back and will not pass through the glass. A common
example is that you can see reflections of images across a lake or
pond, but if you look vertically down into the water, you see into
the water. Same principle here.
So that motherson want to impress the gal, did all the weavings to
show his "skills" and he didn't judge accurate enough. Either that,
or he was really speeding and fail to turn soon enough at a sharp
bend. So he mounted the curb and bang into the beemer. Not
forgetting the beemer also is moving, say 50km/h. Even if the mazda
wasn't speeding at 50km/h, the combined speed is 100km/h. Thats why
the mazda flip. THe beemer being heavier, wins.