Conception occurs when the male gamete fertilizes the female gamete.
That is a good answer, add a bit of your personal fears (don't share here) and it will be good.
If your car is clean you can prevent the risk pr a car accident because if there is a bunch of stuff in the car there is a higher chance you will get distracted therefore making you less aware of your surrounding, causing you to be more likely to get into a car accident.