Wow!! Both the work and the photo set are spectacular. You did the work of blending the Automotion roadway sections together, and at the junction with the layout's static roads much like I did, and as can be seen by your posting it is a lot of work but well worth it. The pads for the gas station and the sidewalks and curbs are fantastic. Truly great work everywhere.
A couple of comments
1) You probably have this planned, but . . . based on experience, wire guided cars occasionally go "of the reservation" - the tiller arm gets slightly tired or bent inadvertently or something and while you aren't watching (I have not had this happen with O-gauge yet, but when I had the N-Gauge Faller system it it would happen, and always while I was looking at something else), so the car jigs where it should have jagged, then it could go off the road, and off the layout!! Ouch. It is pretty easy to fix the steergin - you have to do that stuff covered in AutomotionFX's video to "tune" the steering system back to correct orientation, but the trip to the floor if the car goes off the layout would perhaps do wrose damage. Some guardrails in places would not only look realistic, but will save you a car or two in the future.
2) A have that same AutomotionFX Mustang, and a 2019 model (of my current car) I had them convert. Both have the same traction challenges. Your sandpaper idea is inspired - brilliant. I was also thinking of trying something like Bullfrog Snot on the rear tires to see if it would increase their traction.
