Non resident - How do I buy a car?

[Mr Angry]

I hope on this excellent forum someone can give some advice.
Eventually we intend to make the move and live in Spain. To make the first steps and to save on car rental, I would like to buy a car.
As a non resident and without a permanent address can I use a 'Post Box' address to apply for the necessaries? For example NIE, registered address for car, car insurance etc?

Thanks in advance for any help.

[fpegman]

You will need a permanent address ,what about a good friend letting you use thier address