Finally a method to remove them on PC.
Two step process:
[/Script/Engine.RendererSettings]
r.AllowGlobalClipPlane=0
Note: If you don't have Car Reflections on Ultra Low first, you may have jump back to the menu or exit and restart the game for them to fully disable. Interior Windscreen Reflections may still be visible on higher quality settings if you want them back without editing the .ini, but if you want them gone again on Ultra Low you might need to restart again.
Especially useful right now with the new Citroen C3 which is extremely broken. Before and After examples of that and other cars with elements that would be physically impossible to see reflected on the windscreen but are in the default game:
Not the only cars in the game that are broken here, all sorts of cars in various lighting/time of day conditions are worse than others. I can't believe it took this long to find a workaround, but better late than never.
