The combo bar possesses all the great features of other cars, built into one automobile. The turning radius of Mercedes, the instruments of BMW, the hybrid techology of the Prius...but first, car companies have to solicit the opinions of their drivers to discover what their customers think is the single most amazing aspect of their cars. Then, a designer from say Porsche designs the Combo Car (which needs a better name) with the goal of making a car comparable in price to its component parts. The contributing auto companies share in the profits anc costs, thus limiting the downside. I've always wondered why no consortium of autos has tried this. The consumer would absolutely benefit as would the participating companies.
I drive a lot and have discovered what many cars are good at, and are not. It's a waste not to pool our best feats of engineering, design, etc...to produce something like the Combo Car.