One thing that's more obvious with the G29 Z4 than most of the other recent BMW offerings...
It used to be, the wheels are pushed out as far out to the front corners as possible on most BMWs. Here's a profile of an E46:
Here's an E86 Z4 Coupe:
Here's an E89. Still "small" front overhang but the overbite is growing.
Even as late as the early 201x, the overhang in the front is miniscule.
Considering some of these are inline 6 engines, having the front axle pushed out so far near the edges means the bulk of the engine sat behind the front axle, even on a block as long as an inline 6. Also, the strut towers in relation with the strut makes a very LARGE caster angle. The most exaggerated of which is the first Z4 platform, where the stock caster angle is as high as 7.5º (the M3 by comparison is 5.7º) with the front of the engine block parallel to the central axis of the front wheels.
The M4's front overhang is about the same as the E92 M3.
Look at how much the front overhang has grown on the new 8 series,
5 series:
Older 5er:
G29:
At this point the front wheels are now sitting near the middle of the front fender. This has two negative effects. The engine, unless it's a 4 cylinder, sits on top of the front axle. The car may still "retain" a 50/50 weight distribution, but the more mass is distributed over the actual axle, the less responsive the steering will be. Second, it's unlikely that it's going to have a large caster angle like previous BMWs. Large caster angle leads to sharp, responsive steering. The drawbacks to continue to put the wheels all the way to the corner up front, there's less space to collapse for front collision and pedestrian collision protection. The large caster angle produced by pushing the wheels all the way out to the very corner and reducing the overhang means the front end tend to tramline a lot more than say, a car with minimal caster. So pulling the wheels back sacrifices steering feel and response, but increases drive comfort.
But the biggest impact is still having more of the engine's mass over the actual steering wheels. One of the reasons why many journalists like the 228i over the M235i is because the 4 banger has the entire engine sit behind the front axle, leading to a much quicker set up front and better and more accurate steering wheel movement to turn-in response. Oddly, by moving the wheels back and having the engine sit right on top of the front axle will actually improve the front end grip, at the expense of actual feel/responsiveness of steering. See M2's small-ish front overhang:
I think BMW realized that, as their car continue to increase in length, width, and interior dimension, you can no longer package the car with optimum handling characteristics, but you'll have to start sacrificing that razor sharp handling feel for packaging purposes. That massive front overhang is likely going to result in the 4 cylinder G29 having superior handling characteristics over the 6 cylinder version.
Which, if the engine plans leaked earlier is any indication, the Toyota Supra version with the 4 banger will probably be far superior to the Z4 version with the 6 cylinder engines dynamically.
Mark my words.