I had Paul Mainville's KDTW installed, but when I removed it, the default KDTW was completely messed up... everything was in the wrong place, and the tarmac textures are missing. All other airports are fine though. Anyone know how to restore the default KDTW?

Might be an AfCad file remaining somewhere. Can't think of anything else that would cause this to happen so I'd look for that first. Search for a file that looks something like AF2_KDTW.bgl

Which version of the sim are you using and how did you have KDTW installed....in separate folders of your own creation or in the default Main Scenery and Texture folders?

FS2004, and I had a KDTW folder installed into the Addon Scenery folder.