There are kits with different number of sensors such as 2, 3, 4, 6, or 8. How many sensors do I need?
More sensors will give you better coverage with minimized blind spots. By having 2 or 4 sensors in front and/or rear bumper, you can get better coverage on the corners of the bumpers. Too few sensors may result in blind spots. Also see E-1. Are there any blind spots in rear of vehicle? and E-2. Is there a blind spot in front of vehicle?