Noel, Eoin "super boffin" of DART fame makes some excellent bogie sideframes for the C-class that have real "meat" to them, and I'd recommend getting some, if he has any to spare. The GM sideframes just look totally wrong, and they're easy the remove. When you think of it, the only real detail on the C class is below the skirt, battery boxes, bogies etc. so if you can up the spec there, you'll have a tasty model.*
*aside from the fact that the front looks like it got a belt of a shovel, and the windows are at the wrong height and size.