How can I transport a Madsen bike? I just got a Madsen bike for my wife, and now I am looking at how best to transport it.  I have a Suburban with a roof rack.  The bike is 88" long with the handlebars turned, and I don't know if I should try to find a hitch-mounted carrier or a roof-mounted.  Anyone tackled this?

The Madsen Bike is a cargo bike with a large bucket over the rear wheel.
I doubt it is going to work on any rear rack. You may be able to install two roof racks end to end or buy an extra long one for tandems. 
http://www.rackattack.com/product-pages/thule-558p-tandem-carrier.asp?utm_source=google&amp;utm_medium=product-feed&amp;utm_campaign=google-products&amp;utm_term=100558P&amp;gclid=CKf7rrWemboCFdAWMgodllgADg 

Additionally, it should fit inside the Suburban. 
Another idea would be to stand it up on top the truck after installing some sort of board. The huge kickstand should hold it up and just stabilize it with straps. Headroom will likely be a problem so it might also work to set a blanket down and just lay the bike on its side and strap it down that way. 

I have a front load cargo bike and don't drive it often but when I do need to I just throw it inside my station wagon.