I've owned 2 different kinds of pull up cars. Both took up too much room or didn't really work.
If you work out in the garage or shop, look into making one. In addition to a pull up and chin up, this allows you to do parallel and wide grip pull ups.
Depending on your height or the height of your ceiling, you could change the 12" bar to 10" or 8". It cost me $73.
Hope this helps someone...