No, a car will not start with the battery polarity reversed. Reversing the battery polarity means that the positive and negative terminals of the battery are connected incorrectly. This can cause damage to the vehicle's electrical system, including the starter, alternator, and other electronic components. It can also cause sparks and arcing, which can pose a significant safety hazard. In some cases, a reversed polarity can even cause a fire.
If you ever accidentally connect the battery backwards, the best thing to do is to immediately disconnect the cables and inspect them for damage. If any of the cables or components are damaged, they should be replaced immediately. It is also important to inspect the car's electrical system for any damage, and to repair any problems that you find before attempting to start the car again.
