There are 1/43 or close to cars at the Disney store on sale now.
They look a bit big for this and are from the 2nd movie, but some characters from the first.
The cars for these buildings are closer to 1/64 which works well for American Flyer or 0-27
Better get the cars while you can Walmart and like are blowing out the old stock to clear it out. You might be luckly to find the Flos at Toys R Us they had them at one time.
They make fun background buildings for the cars movie.