Each kennel is a little bit different. We have used the one at Magic Kingdom and MGM in the past. At MK they have little parking area in front of the kennel for drop-off and pick-up. You cannot leave your vehicle parked there while you go to the park. At MGM, there is no dedicated parking for the kennel. You basically tell the lot attendant/security that you have to go to the kennel and they let you drive up to the front parking area(I cannot remember if it is the handicap area or just some other special parking area). Again you cannot leave your vehicle parked in this area while you are in the park.
Also, if you are not aware, they are sort of self-serve kennels. You are required to come walk you pet a certain number of times per day. I think once for the day and at least twice for overnight. Even though you can leave your pet overnight, they are not staffed 24 hours a day. After hours, you have to use the courtesy phone in the lobby to call security to let you in. The staff is usually very good. Our Dalmatian is not always the friendliest, but they gave him great treatment. Our guy is more of a family member than a pet, so feel free to ask any questions that you might have about the Disney kennels.