The Nfs08DemoRelease.exe file you have requested: Official Demos / Need for Speed: ProStreet Porsche US Demo - 570.61mb is not available. Perhaps try browsing all files for the game Need for Speed: ProStreet and upload any files you want to share or are missing. This is the only information we could locate:
EA has released a second demo for Need for Speed: ProStreet. This new demo features 2 Porsche cars (911 GT2 / 911 GT3RS) drivable on the Porsche Leipzig testing track.