I've build a rig but with triple screens. I can adjust the seat height of the auto seat, but unfortunately I have not made it, so that my eyes can be in level with the center of the screen. (Have to fix this some time ). Fortunately there is an option in iracing (VANISH-Y) to compensate for the fact, that i dont see the virtual world perpendicular to the screen. Do anyone know if there is a similar option in rfactor 2? Right know geometries(very noticable with straight lines) going from the center screen to the side screen are not straight. In a non practical way i can fix this by removing the seat and sit on a pillow on the floor In other words i lower the physical seat height and lines are straight... Maybe there is another option available to fix this. I wished that i had considered this when building the rig..
There is an option pitch in the ingame controll menu. You have to make two (up and down) key combo's CTRL and any key you like in control menu When in car press that combo and your horizon wil go up and down. Hope this is what you meant ?