Yes, it is possible to run an air conditioner in your car and roll down the windows at the same time. However, doing so may reduce the overall cooling efficiency of the air conditioner.
When you roll down the windows, you allow hot air from the outside to enter the car, which can counteract the cooling effect of the air conditioner. The air conditioner works by removing heat and humidity from the interior air, but if you let hot air in from the outside, it makes the cooling process less effective.
If you want to maximize the cooling efficiency of the air conditioner, it's generally better to keep the windows rolled up while it's running. This helps to create a more controlled and insulated environment inside the car, allowing the air conditioner to cool the interior more efficiently.
That said, many people enjoy the feeling of fresh air when driving and prefer to have the windows partially or fully rolled down. If you find it more comfortable to have the windows down while the air conditioner is on, you can certainly do so. It might not be as efficient in terms of cooling, but personal comfort and preferences are also essential factors to consider while driving.
In extremely hot weather conditions, you can use a combination of rolling down the windows and running the air conditioner to balance between fresh air and cooling. You can roll down the windows initially to let out the hot air accumulated in the car and then switch to the air conditioner to maintain a comfortable temperature. This approach can be more effective than running the air conditioner alone with the windows fully down.