Is it possible to have an immage as a background in the modeler so it can be used as a template?

There must be a way to put something in as a template to trace it directly in Carrara. I know that InfiniD could do it at least in the spline modeler. A workaround might be to create a rectangle, go to the texture room and apply your image, go to the modelling room and use that image as the template. I haven't tried this but it might be better than nothing. (Especially if you don't have Illustrator)

A work-around is to add extra cubes/faces (one for front & one for side profiles) to the Assembly room and then map your image to theses cubes. Place them at right angels to form a corner. Then position your model to be centered on these cubes. In the model room, display your Scene Preview window in 2 or 4 views mode & use the texture-shaded preview to display your images. Not quite as elegant as Infin-D but you do see real-time changes to your model in varied projections.