How to change a mesh material using a button in VR (HTC Vive)

So I’ve been struggling for a day and a bit now to figure out how to change the material on a mesh using a button.
It’s probably really simple but I am fairly new to Unreal, sorry.

This is the setup I am using (he has the files available to download in the description)

I can’t figure out how exactly to set the blueprint up.

I try to replicate the set up that works and I can get this far:

Original one that works:

However when I go to create my custom event this happens

I don’t have the option to set the visibility of my car mesh (I have tried using the straight up mesh referenced in a variable as static as well as a blueprint).

If someone could tell me how to correctly set this all up it would be really appreciated, thank you!

Does the car exist in the world?

Yes, I tried dragging the mesh into the level and also attaching it to an actor blueprint

If the car is placed in the level as part of the level instead of being spawned, you can use GetAllActors of Class node and loop through until you find it, or give it a tag and use GetAllActorsWithTag (probably better).

Also there is a show/hide bool on Actors in the world, HiddenInGame which you can turn on and off. See if that shows up.