Just if you have one damage that must be repaired from a professional the low price of the doordefender has been amortized.
Of course - that is what the doordefender is designed for. The magnets are strong enough to keep at the right place but on the other hand can be de-installed very easy and carefully.
No - the contact area on the doordefender is covered with a smooth textile that will protect your car painting from scratches, also when snow, dust or dirt is between the contact area. All connection cables are covered with rubber hose to avoid any scratches caused by the doordefender itself.
Actually not. The standard doordefender can be put together using both contact areas. They are designed to harmonize magnetic forces to keep both bolders together and to avoid rays of magnetism to the surrounded car electronic.
Taking care of the doordefender it should go along with you a very long time. After 10 years most of all sold doordefenders are in operating state. The special weather-resistant surface and the strong magnets didn't loose their purpose yet.
If you forget to install the doordefender while parking it may happen that your car neighbour slashes his door against your car door. Better mount the doordefender always in close parking situations.
Normally you pay from 50€ depending on the deep of the impact and of the location. Some places at modern cars can only be refurbished by lot of work and that does cost money. Avoiding just one dent has amortized your investition in the doordefender.