No regular car would lift off the ground on a flat surface. Cars are designed to be aerodynamic, which means that they are designed to cut through the air with as little drag as possible. This is important for fuel efficiency and for safety, as it helps to keep the car stable at high speeds. However, aerodynamics also means that cars are not very good at generating lift.

In order for a car to lift off the ground, it would need to be traveling at a very high speed and it would need to have a lot of lift generating surfaces, such as wings or spoilers. Even then, it is unlikely that the car would be able to stay in the air for very long.

The only cars that are capable of lifting off the ground are specially designed race cars or aircraft. These cars have wings or other lift generating surfaces that are designed to generate enough lift to overcome the weight of the car. They also have powerful engines that allow them to reach very high speeds.

For example, the Bugatti Chiron Super Sport 300+ can reach a top speed of 490.484 km/h (304.773 mph). This is the fastest production car in the world. However, even the Bugatti Chiron Super Sport 300+ would not be able to lift off the ground on a flat surface. It would need to be traveling at a much higher speed, such as 1,000 km/h (621 mph), in order to generate enough lift to overcome its weight.

So, to answer your question, a regular car will not lift off the ground at any speed. It would need to be traveling at a very high speed and it would need to have a lot of lift generating surfaces in order to do so.