How is your Car hauler Rigged Up?

Here's a real newb question... I have never paid any attention to people loading and unloading their enclosed trailers. Can you drive in and get out of the car just by opening the door? Or do you have to winch in, and push it out??? Doesn't seem like there's much room to open the car door unless you've got an extra door on the trailer on the drivers side.:dontknow: