what you want is called DETOURS... its a source code provided by microsoft that shows how to reroute api calls to your own code. of couse you will need another application active during runtime to detect and inject your dll into the game.
you could do this without detours but you would need to find the exact address of the d3d pointers
here is the source for dll injector and a test dll etc.. its for d3d9 but should be easy to convert to d3d8
really? i'm not sure, i was just copying the one from NFS Underground.... the 1st one
there is a few bugs with this one, especially when spinning and going in reverse... im thinking to make a points system like NFS so that has to be fixed