Question 1:
I am currently making a vehicle that need to have its front heavier than the back. For instance, If I jumped off a jump you would go up and then the front would fall faster therefore you would land on your front tires and then the back tires would follow.
Question 2:
Is there a way to increase friction between the ground and the car? Also (I thought I saw this somewhere) can you adjust the gravity.
Sorry for all the questions all at one, thanks in advance.
One way to make your car heavier would be to attach a rigid body weight to the front using a joint constraint.
Friction is in the DYN panel in the material buttons, gravity is in the world settings.
Actually, having the front be heavier shouldn’t help you at all. In real life, objects that are heavier do not fall faster than lighter ones; Galileo actually proved this, accoring to tradition, by dropping two objects from the leaning tower of Pisa
I know this thread is kind of old, but forgive me; I couldn’t resist. 
In the case of the car example this would actually work. Not because of gravitation, but because of inertia. If you were to apply the same amount of force to two objects of different weights, they would travel at different speeds. Assuming that the car would not be dropped off a crane (or the Tower of Pisa) but instead driven over a ramp, a heavier front would hit the ground first (unless the car flipped completely)