hehe me personally ... i dont use the macro setting ... i stand back a little bit and zoom in on the car ... better depth of field that way then from the macro setting ... plus then you can use a flash as well to kill some shadows (or photograph on a nice overcast day outside) ...
3.2 mp is good enough
optical zoom > digital zoom
compact flash memory card = cheapest memory out there
built in flash is a plus but one that will also accept an external flash is good to
most cameras have a poritrait setting on the configurations ... that works the best (as far as presets go) for taking photos of a model car ...
lighting and background of the model a lot of times can make a picture ... more then having the right mp camera ...