No math major or trig needed here. What you're trying to do is rotate the car about the rear axle. Just set the weight times the horizontal distance from the CG to the rear axle equal to the unknown force times the vertical height of the CG MINUS the height of the axle, and solve for the unknown.

weight x length 1 = Force x (CG Height - axle height)

Force = (weight x L1) / L2
where L1 is the distance from CG to axle
L2 is the height of CG minus axle height


Now us good ol' F=MA to determine what acceleration is needed to generate that force.