Is MGM Really Landlocked? Ok, I am not an Engineer, an Imagineer and sometimes cant figure out the working end of a Screwdriver - but - I think there may be a way to expand the Studio's to accommodate a Radiator Springs type ride.
To begin with - I compared Google Maps of DCA (and the Radiator Springs area) to the Lights, Motors Action area - simply not enough area to accommodate the ride - let alone Restaurant, Shops, etc. Thus other attractions would have to go.
The other problems, as the poster stated: the 2nd Entrance runs immediately behind the area in question.
But, thinking about it, could they not just employ a Bridge and elevated road system over the road which leads in to the parking area- akin to what they did for the outdoor portion of est Track (which sits 30 or 40 feet above the parking lots below? Thus, a large portion of track sits on a "Table" which runs out of the existing park. The table supports the Track and the Desert Landscape facade. The existing 2nd entrance then runs under the "Table" which holds the Radiator Springs Track.
I guess the feasibility lies around the land you are working with. Is it wetlands? Do large granite deposits sit down there (what they ran in to building the Monorail extension to Epcot)? I do see a small Pond and Creek back there - maybe that is an issue? Maybe my idea is much more expensive?
If the land was suitable then you would not have to carve up the existing road work. I would think this also might mitigate any Power concerns as the existing power could be run out to the track.
It is probably a silly suggestion. Like I said - I know very little about construction, electrical requirements, land usage restrictions, etc. But - I do know that Disney and others have overcome more challenging obstacles.