I want to start running this game but I have some frame rate issues in the driving missions. The game will slow down to 80% most of the time and it is really bad because the sound and music are really slow and bad. But worst of all is that the game slows down.

you can also drive in first-person by hitting the Z-button. That reduces some lag but it may be a problem with emulators in general. Nightfire is not very optimized on emulator.