okay I just found out this is a Halloween Feature, I’ve been bamboozled and I love it.

Hey, I use Railcraft 12.0.0 and my trains look like this. Pic 1 with Shader, Pic 2 without.

They work just fine but the textures are weird - I started to think that other mods might be interfering but just with Optifine installed, this problem occurs.

There are 11 (closed) issues that come up when you search for "ghost carts". Maybe that's a good place to start.