Q: My battery keeps going dead if I don't drive it everyday.

If your battery is in good condition, you might have an "electrical leak" And you may be spot on about the trunk sensor. But it could also be many other things. When the car is shut off and closed up, it takes about 30 seconds for it to "go to sleep" where it shuts down all of the body systems. If any one sensor is not indicating that something is not closed, the body module will not go to sleep and continues to draw power. To check this out, a technician with the appropriate equipment can plug into your car and read the state of all the sensors on a computer screen. Another method is to hook an ammeter up to your battery to check for a drain then examine the suspect circuits and devices to isolate the drain. Any way you look at it, it needs a proper evaluation. Simply replacing parts until it is fixed can get very expensive quickly. I recommend you contact YourMechanic to have a technician come to your home and inspect the car’s battery system and help you decide what to do next.