Solar panels don't really collect enough energy compared to what a normal car consumes to keep going.

In addition to that the panels will add cost and weight to he car. Under bad circumstances solar panel may actually decrease the range of a car rather thane extend it, because the car consumes more extra energy to carry the weight of the panels around than the panels give it.

There are some extreme cases like specially built racing cars that are ultra light and race through Australia with the power of the sun.

For normal cars that have things like safety features and amenities and drive though places that are not desert it would not work.

This is not an engineering problem that can be overcome with better technology, there simply isn't very much solar energy that hits a patch of earth the size of a car. and the minimal amount of energy to move something the car even with the most efficient engine is also fixed. Those are hard limits.

It makes much more sense to put some solar panel on the roof of your garage and charge the car while it is in there (potentially overnight with the help of a battery).

Another way to look at this is to look at nature.

Plants are solar powered and animals are powered by eating plant or each other.

Why doesn't a cow simply start doing photosynthesis so it has to eat less grass. Mostly because evolution does not work that way, but also because the amount of solar energy you can collect from the area of a cow hide is so much smaller than what you ca collect in a meadow full of grass.

There are some animals like sea slugs who do some photosynthesis but they don't need much energy because they don't move around much. A sea slug floating in the water needs less energy than a cow that keeps running around.

So you can totally power a car with solar energy alone, provided you either collect the solar energy outside the car and let it harvest it like a cow eating grass by plugging it in, or you can put the solar panels on the car but than you have to build it ultralight and only drive it in the desert, or you can build it like a normal car and put solar panels on it but simply not move it much at all.