[urq] "new" AWD systems

[Dave Ritter]

As I know them,
AWD ala BMW
	"ix" Transfer case, viscous couplings in center and rear diff, rear bias via 
transfer case center diff.
	"early xi" Transfer case, open diffs, rear bias via transfer case center diff 
fly by wire throttle, abs controlled brake application to stop spinning 
wheel, followed by traction control throttle reduction.  Same as benz ML I 
think.
	"xi xdrive" Transfer case, some sort of clutching to direct power fore and 
aft from center differential in case of front or rear traction loss along 
with abs controlled brake application to stop spinning wheel, followed by 
traction control throttle reduction.

AWD ala Subaru
	Manual shift excluding STI
Viscous coupling center diff, viscous rear diff some models.
	STI
Variable automatic front rear torque split with manual override. Limited slip 
diffs front and rear.
	Automatic shift
Electronic clutch controlled center diffs, normally front bias 
Stability control available on certain upscale models, VDC, LL Bean..