Dan, if you struggle with immersion in LFS, drive in cockpit view (custom if you need), with real dials, analogue speedo (makes it harder to see so you don't look at it in corners) and the HUD disabled. If you want to check your split times in a race, have a shift+F button on the wheel to hide/show the HUD.
And, hasn't Scawen mentioned somewhere that he would like to add track bumpiness to LFS, at some point?