Jockbod48 saidI think it's a laudable ambition to turn an old but interesting place into a mixed use of homes over retail shops. Sure, there are environmental problems to clean up in the soil, but that can be done.
Here's an example in San Francisco. Condos are being built over restaurants and shops, in the old Ghirardelli Chocolate Factory. While the Packard project is much larger in scope, you can get an idea of what the condos look like from the photos. They look great. The exposed original brick walls and large windows give a loft like, industrial look that is very attractive.
to compare a chocolate factory conversion in SF and this project is ludicrous. Detroit is NOT SF, it's a radically different (non-existent) housing market, and has been mired in decades of scorched earth economic landscape. while SF is one of the richest per-capita cities in the WORLD.
Also, the soil would be the least of the problems as far as clean up goes. an auto plant is going to have walls floors and ceilings covered and saturated with heavy metals, zinc , cadmium, lead, asbestos, formaldehyde, rubber, and every petro-chemical under the sun, and who knows, maybe residual radioactivity.