wow - you must be in southern OH cause this Dream Cruise thing has been gathering momentum for 10 years.
At the point now where 1-2 million people will be in attendance.
It's on Woodward Ave. which runs from downtown Detroit to Pontiac.
Most of the people/cars/corp. tents are from 9 mile - Pontiac.
Runs from 9am - 9 pm on Saturday - 8/18.
It's not much fun to drive on Woodward during this time unless you have 1) lot's of cash for gas and 2) an extreme cooling setup e.g 4 core alum rad and electric fan.... cause it's basically a parking lot...
But, as a spectator it's great entertainment - cool cars - great people - lot's of activities
more info - check this link:
http://www.woodwarddreamcruise.com/