Here is my thought on redoing the Autopia. blow up everything... the current track, queue, and lawnmower cars. Make one track and have all the vehicles run on an electric guided rail, similar to Cars/Test Track... except vehicle loading is similar to the TTA. Step onto moving walkway in sync with slow moving vehicle... once loaded and vehicle leaves load area... it accelerates to a faster speed, and wider spacing, like TTA. The ride takes you past several scenes from Cars, but because of the footprint... you won't go fast like in California. The vehicle arrives back at the load/unload area and slows to Omni-mover speed for unloading. Single lane track would allow for a longer ride and room to build multiple scenes to 'cruise' past. Since the vehicles running are not as fast or large as the Carsland/TT ride system... it will be less prone to breakdown & replacing tires all of the time.
Downside = Cars 2 & 3 were not as well received and this IP redo will be expensive & may not give good ROI to the MK.