Just for fun:
I made a mod, so every vehicle that is in game without mods, has now some real deal backfire. Just select the part in Additional parts Backfire, like in this picture.
It may not be too realistic and for some vehicles it doesnt work with some exhausts, so you just have to put on a custom or race exhaust or even take it off. It just makes the normal Beamng backfire more extreme, no custom textures etc...
This is how it works:
vid by me
!!! ATTENTION, IF YOU HAVE A GRAPHICS MOD OR RESHADE MOD INSTALLED, THE FLAMES MIGHT NOT BE VISABLE!!!
Have fun!!
Known issues:
-the flames dont work for some people, i cant figure out why, it works on all my windows pc's -> try clearnig cache and other stuff
-Flames may disappear after some longer time of driving with the mod turned on
PS: Im still working on my other mod, check it out!!!

Experimental Backfire Mod 0.001
adds some flamey action to every stock beamng vehicle