[SR2] Only motorcycles spawning

[Professor Flubbman]

I recently completed SR2, and I now spend most of my time screwing around with cheats, including Evil Cars. I find that motorcyclists trying to crash into me create the funniest situations because they fall off they fall off their bikes so easily, but sadly they don't spawn very often.

Is it possible to make a mod that increases the spawn rate of motorcycles and decreases the car spawn rate?