PDI, or delivery, is the charge for a technician at the dealership to inspect the car to make sure it has no cosmetic or mechanical issues. Just because a vehicle is brand new from the factory, doesn't mean it's ready for you to take home. It's also for the wash crew to run the vehicle through the car wash and make sure the car is presentable for the new owner. They'll also apply any final touches they need such as filling up the gas tank and topping up fluids.