a) if it's vehicle specific, in respective cam file under "LocalCam=COCKPIT" section (usually second) increase the "ClipPlanes=(0.xxx, yyy.000)" line's first value (0.xxx ; usually it is something like 0.075 or 0.175) as much as u can just before u start seeing parts of the ingame cockpit disappear
b) if that doesnt help there is a global but more "brutal" method: in track's .scn file under section "View=mainview" theres a line "ClipPlanes=(0.xxx, yyy.000)" once again. this time just replace it with: "ClipPlanes=(0.50, 10000000.00)"
be aware that with the second method if the track's object LODout's are not optimized you may experience a decrease in FPS though