http://cvk.pethu.se/ is hosting a nice and free utitily called CabViewKeys. CabViewKeys allows you to "turn your head" in the cab using the numeric keypad.
Manual included in the download, in case you want to create some macro's for you own custom engines.
Now if we coould have the same kind of utility for Shift-2 views, using the cab windows, the platforms and the stepwells while switching cars in a yard ....