Transporting a vehicle because you're moving or you've sold it to someone isn't the same as calling a tow truck for a broken-down vehicle. A transport service won't be delivering the vehicle to a repair shop and will usually need to travel a greater distance, and you may need some extra precautions in place for a sports car, antique vehicle, and the like. Note a few questions to ask a transport service when you need your car delivered to a new home rather than simply towed.
Always ask about lead times
A towing service may be able to arrive in a few hours when you're broken down by the side of the road, but note that this is typically because they're simply towing vehicles a few miles to a repair shop, as mentioned above. If they're hauling your vehicle across the state or any such distance, they will need more time to schedule that trip. Always ask about lead times before making your plans and call as far in advance to schedule the transport as possible.
Ask about putting a car cover on the vehicle
You may assume it's a good idea to cover your vehicle, but a car cover can cause a traffic hazard if it flaps around while the car is being transported, and it may get in the way of the tie-downs used to secure your car in place. Some protective films may be allowed, or a transport company may suggest a trailer for transport, if you're very concerned about the car's overall condition during transport.
Ask if your vehicle will need special preparation
If you're transporting a sports vehicle, an antique vehicle, or a vehicle that has been customized or modified in any way, always ask if it will need special preparation. A transport company may need to see the vehicle or at least photographs of it to note if there are parts that could be hazardous during transit or that won't fit their tow vehicle properly. As an example, a vehicle with very high lifts may not fit the back of a tow truck bed and may need an enclosed transport. An exposed engine, such as for a sports vehicle, may become hazardous during transit and will also need an enclosed trailer. If you're having any type of custom car or unusual vehicle transported, ask about this ahead of time so you know how to prep it properly, or will know if a trailer is needed rather than a tow truck with a bed.