How to apply gravity to certain objects only

So right know i know that you can apply/change gravity to the entire workspace, however can you somehow make gravity dependent on different objects
Like making a car have more gravity than a ball

My approach to this would be to have an additional BodyForce inside that specific object and apply a force to it. If you want a specific force dependant on gravity exactly, you can do the following:

local object = ...;
local gravity = 9.81;
obejct.BodyForce.Force = Vector3.new(0, -gravity*object:GetMass(), 0)