The car initially is at x = 6.5 m and y = 2.5 m and its velocity is Vo= (4m/s)i +(-4m/s)j.
The acceleration acting on the particle is a=(1.5m/s^2)i + (1.5m/s^2)j. The component of this acceleration acting on the x-component of the velocity is 1.5 m/s^2 and the component of the velocity acting on the y-component of the velocity is also 1.5 m/s^2.
In 4s, the x-component of the velocity due to the constant acceleration changes from 4 m/s to 4 + 1.5*4 = 10 m/s. And the y-component of the velocity due to the constant acceleration changes from -4 m/s to -4 + 1.5*4 = 2 m/s
After 4 s the car has a velocity with an x-component of 10 m/s and a y=component of 2 m/s.