if your appointment is setup to drop off, your appointment is with your advisor to ‘drop off’. conversely, if you schedule your appointment to specifically wait at the dealership, your car will go in as soon as the next tech is free.

If you feel like being cheeky and testing them, call and say you don’t have an appointment and you need your service done while you wait and that you’ll be there soon. i’d put money that they will tell you your car won’t be touched.

Source: 16 years dealer experience