There’s probably as many stories about where as there are storytellers. :^)
http://www.google.com/search?q=jimmy+hoffa+renaissance+center
Yup. I knew the jets stadium one is false, because why truck a body cross-country when you have perfectly good car crushers or cement contractors or pig farms.
I had a call once on what it would take to do a magnetometer survey over the Everglades to look for a 55 gallon drum. Seems these guys had a lead that Jimmy had been chopped into pieces, put in a drum, and then dropped out of a plane!
I told them “good luck!” (Impossible project, and “treasure hunters” never pay.)