What type of car is it?
How much does it way?
And I second the use of a car hauler, or even a dolly if appropriate.
The car haulers and dollies are small and are not that hard to tow, just slow down and pick a time of little traffic, say 2:30 am.
If you rent a car hauler or dolly make sure you get good tie downs some of the rental tie downs can be pretty worn. If you don't know how to use them ASK or get someone to show you. The only dumb question, is the one you don't ask. Trust me you don't want the car comming off the trailer.
Check the overall condition of the rental equip. don't worry about paint or appearance, check the tires, the safety chains, the the part that goes over the ball (make sure it operates correctly), and make sure the lights work.
By the way I've done some pretty stupid stuff while towing, if you plan ahead, are carefull you should not have too many problems.
Most of all be safe. Remember you stopping distance will be dramatically lengthened thus the plan ahead, no tail gating.
Some day I'll tell you about the time I towed a 74' Blazer on a tandem axle trailer with my 82' Datsun pickup, which had the massive 2. 2L Isuzu diesel in it.
lol