Which car is the lead car when traveling south from Frankfurt to Nuremberg on ICE627?
Why does it matter? You are not going to see out the front, past the engineer. All cars arrive at the station at precisely the same time.
Lee, the ICE-3 rolling stock have some "Panorama lounge" that allow you to see through the cabin. It is a unique fetaure of this train (new ICE models will not have it, old ICEs don't either). There is just a glass panel behind the driver compartment that you can look through. Some people also want to make seat reservations specifically on the direction of travel (or opposite).