this is just hysterically funny!
Im terribly afraid of roaches too. But there's no reason to do an astrology chart on them. Go get a flash light and check your car at night. Do not leave food /drink / trash in your car.
And sprinkle a bit of
Borax Acid in your trunk (where no child or pet can reach) and it will get rid of them pronto (if there are any in there). You can get Borax Acid for a dollar or two.. it kills roaches and ants very quickly!
Roaches will not infest your car if there is nothing to feed on. They go for the grime and food. Most likely, it was a little stray if your car is squeaky clean.