Ok, after looking during the weekend, I found a cool pdf document. It explains a lot about the ms6. I suggest, save it.
http://www.3dluvr.com/crossbow/vir/speed6.pdf
Like I said, there are a lot of sensors to try and retrofit in the ms3, so is better to think of something different. The 4WD ECU uses real-time data to manage torque:
PCM: VSS, RPM, TP angle, neutral switch, brake pedal position, selector
lever position
DSC: 4-wheel speed sensors, parking brake switch, ABS activated, steering
wheel angle, brake fluid pressure, back-up light, coupling torque request, yaw
rate, and lateral G-force
Rear Differential: oil temperature.
And for the Volvo s40 setup, I found a couple of pics for the suspension layout, but the pics are for the fwd model. Looking at this pics, the layout is very similar to the ms3, I dare and say, the same? These are ms3 and S40 pics for comparison.