This question seems like a good excuse to try and summarize some of the manifesting knowledge we have on Inward Quest. I'll amend this answer as I find or remember other related answers

How to metaphysically manifest a new car step-by-step...

Question 1 - Do you need the car as soon as possible or can you wait?

• Can wait - Go to question 2

• As soon as possible - you risk getting too needy about what you want which is a manifestation killer but there is still an overall approach you can use. Your expectation about your new car is key to this more deliberate manifestational approach. You could also get hold of a copy of Abraham's Ask & It Is Given - perhaps the greatest book on deliberate manifesting that exists - or try some belief-changing methods (like The Focus Blocks Method) to mold your expectation further. But remember to only use the processes for the fun of using them, not to try to force a manifestation to happen, otherwise you risk blocking your manifestation.

Question 2 - Can you forget about your desire for a new car for a while and just let the Universe do what it needs to?

• No - Go to question 3

• Yes - Use the approach in The Manifesting Box Method

Question 3 - Are you unhappy with your current car, or method of transport?

• Yes - You will need to find some way to make peace with your current life situation otherwise you will again just be blocking your new car from coming. Abraham's Positive Aspects process (more information here) is quite useful in doing this assuming you are not too unhappy. If you are really depressed about your lack-of-car situation, you will need to move up the emotional scale and you may need to get angry about your situation in order to improve your current feeling. Another thing to bear in mind is that you feeling miserable about your current situation can cause unwelcome manifestations unrelated to your current car situation.

• No - In this case, you are either feeling neutral or positive about your existing car-related life circumstances. Good, because this means you are not standing in the way of it coming. Appreciating your current car (or anything else in your life) will speed up the manifestation of your new one. You can also still go ahead and try the method in Manifesting Experiment 1. Most other manifesting techniques you know about (like creative visualization) will also probably work for you in this case but they are all optional because your new car has already been created in the moment you wanted it...if you were to do nothing else but get happy, you would still receive it.