There are a few things you can do to secure a car to a trailer. The first is to make sure the car is properly secured to the trailer. This can be done by using straps, anchors, or bolts. The second is to make sure the trailer is properly secured to the car. This can be done by using straps, anchors, or bolts. The third is to make sure both vehicles are parked in a safe place. This can be done by using a parking lot or by securing each vehicle with a chain or padlock.