The original game lacks native support for 16:9 or 21:9 monitors, resulting in a stretched or letterboxed image.
With the Multifix installed, you can finally experience ProStreet the way it was meant to be played: fast, loud, and—most importantly—functional. xavier 39-s nfs pro street multifix
Acquire the Multifix files (usually a .zip or .rar archive). The original game lacks native support for 16:9