For the abstract "you can do anything" product, you want an open ended interface, but if I'm, eg, renting a car, is a free form text box really the way to go? T

For the abstract "you can do anything" product, you want an open ended interface, but if I'm, eg, renting a car, is a free form text box really the way to go? The rental company knows exactly what information they need from me before they'll rent me a car, so a free form text box so the computer can ask me questions one by one vs a traditional form, seems suboptimal.