Unfortunately the tarus and falcon have nearly nothing in common except that they have 4 wheels and branded by ford.
http://madmaxcars.com/ maybe able to help you if you are wishing to import one.. they usually deal with 25+ y/o ones but would be useful to talk to.
You might be able to get a "xr type" body kit made up for your taurus, talk to a good fiberglasser.. Show them some pictures of a XR6, they might be inspired to sell kits, there are alot of taurus's that could use a body kit..
There is actually a web site where american car owners try to make there cars look like australian ones (mainly like the ones off mad max but there have been other attempts)..
Another option where people have registered a Nissan GT-R as a Nissan maxima. I would imagine you might be able to pass a XR6T as a highly modified taurus. If you know the sort of people who could cut out the VIN plate and weld it onto the XR...
Not sure how legal it is.. Apparently people have not generally been busted for it.