It’s intractable unless you assume the entire weight of the car is supported by air pressure, which is ridiculous. The rubber should be as thin as a balloon. The sidewalls of the tire actually support some of the weight (more on narrow tires).
However, if the side walls are absurdly fragile, you can use the equation P = F / A, where P is pressure, F is force, and A is area.
The total contact area is 4 * 0.028 m^2 = 0.112 m^2. The pressure is 1.9 * 10^5 Pa. Resolution:
P=F/A
P*A=F
F = (1.9 * 10^5 Pa) * (0.112 m^2)
F = 21280N
The weight of the car is 21280 Newtons.