Hi Kai - MoI is actually loaded with a lot of features for precision modeling so it's probably a good fit for the kind of stuff that you're describing.

The various drawing commands in MoI allow you to click points with the mouse (with a lot of snapping options) or also you can input numeric data if you want to make things of a specific dimension.

For example if you want to create a circle with radius of 5, then in the second step of the circle command where you are specifying the radius, you just type in 5 and push enter to create a circle with that specific radius.

Other things are similar - if you draw a rectangle you can type in width and height. If you're drawing a line or polyline, you can type in a length value to activate distance constraint to make the line that particular length in whatever direction you then click in. You can also enter in things like polar coordinates to give a line a specific angle and length at the same time (see here for more info: http://moi3d.com/2.0/docs/moi_command_reference1.htm#__XYZ%20/%20Distance%20/%20Angle)

So I mean as far as accuracy goes, there is a whole lot of functionality in MoI to enable accurate drawing, it's really a major focus of the program.

For images you can use the View > Image command to bring in an image to use as a background for tracing over. I think that a couple of the tutorials listed in the wiki do that, try the ones for cars: http://moi3d.com/wiki/Resources#Tutorials

- Michael