Hi, guys!
Thank you for the informations about my project Mr. Wood, really appreciate it. 
I might make optimizations on my project and add a multiplayer section too it.
The mesh morph only flickers in certain versions of the engine. It had this flickering before only in 4.9 but after that it was fixed until 4.17 and this flickering reappeared in 4.18 unfortunately.
I didn’t tested/thinked that it will have problems with landscapes. Are you using the default car which comes with the project, or are you using a different one Mr. Wood?
I’m using the built in vehicle physics in unreal engine so it might be not perfect or the colliders aren’t perfect, have you tried to increase the tire colliders size in the back/front tire blueprints?