Howdy from Tucson!
If you have a 'burban keep the tandem inside and out of the elements and save the hassle of lifting bike up.
Oh, more than one person has driven into the garage and forgetting about a bike/tandem topside . . . CRUNCH!
We carry our custom Zona tandem inside a Honda Accord station wagon; remove one wheel and it fits just fine, but then again we have a rather short wheelbase: 63 1/2 inches. A standard length tandem would fit with both wheels removed.
A tandem inside a vehicle is less like to be noticed/stolen when parked.
However, your choice!