Their are two key areas which must be worked when looking to increase vertical jump height. One and the least thought about is the core muscles, these will help transfer the power from the upper body to the lower and vice versa. This will allow you to use the power that your arm swing gives you.
The other area to work on is the lower body. This will increase the explosive power in the legs. Try these exercises all performed with heavy reps to failure;
Squats
Leg press
Cleans
The key to improving the jump height is to fool and retain the body. This is done my using steps set to heights you can jump. Take 2 heavy weights one in each hand and jump twice on to the step and repeat this the body begins to adapt to the weight you are carrying, then perform the jump again (3rd time) with out the weights, the body expects the weight to be their and compensate for it, even though it is not their. This allows you then to jump much higher. Keep working on this and you will be jumping higher each day and week. If practiced enough you will get to the point were you can jump over cars, both width ways and length ways.