If you are going to take your bicycle out of town by car, remember a few simple rules from the professionals http://www.flashmoving.net/ that will help you keep your bicycle safe and in full working order.
If you get caught in the rain on the way (or you know that there will be inclement weather), then put the bikes in covers or at least cover them with plastic film to protect them from moisture and avoid the consequences – corrosion on the frame and other elements.
Do not leave your bike near a car or on it without a lock. And even in this case, you should not leave the car for a long time.
If you leave your car in a parking lot and go for a ride in the woods, it is better to
remove the bicycle mount from the body – it is not cheap, so it can attract the attention of thieves.
When driving with bicycles attached to the car body, remember that the total weight of the car has increased, and the aerodynamic characteristics of the car have changed – take this into account when maneuvering, sharp turns and passing under low bridges (if bicycles on the roof).
If you have fixed bicycles with special fasteners on the rear of the car, then do not forget about it when reversing in parking – remember that now your dimensions are 40-50 cm more (depends on how exactly the bicycles are fixed and how many of them).