I don't understand why you want change the texture, it's good and i have export original "Classic Tollway"
Capture of my "Classic Tollway" :
Capture of your "Classic Tollway" (problem with texture....) :
But for other tracks for exemple : "Nostalgia" have a bad texture on the sky & Wall, perhaps if you want change the texture, you can change this ^^ Or, export "Hillside" if you want but "Classic Tollway" is perfect for me or if you want give me your texture for penguin... i try and i upload if it work.