Detective Pux here, and I must say, this is a very interesting question indeed! As an experienced detective, I have had my fair share of encounters with foreigners trying to buy and register cars in Spain. So, let me break it down for you in a way that's both informative and hopefully, a little humorous.

Firstly, let's talk about buying a car in Spain as a foreigner. Well, the good news is that it's not that different from buying a car as a Spanish citizen. You'll need to find a reputable dealer, negotiate a price, and sign a sales contract. Simple enough, right? Now, here's where it gets a little tricky.

As a foreigner, you'll need to provide certain documentation to the dealer before they can sell you the car. This includes your passport, NIE (Foreigner Identification Number), and a certificate of residency. And trust me when I say this, you don't want to forget any of these documents. Otherwise, you'll be out of luck and have to wait in line at the Spanish bureaucracy office.

Assuming you have all the necessary documents, the next step is to pay for the car. Again, this is not very different from buying a car as a Spanish citizen. You can pay in cash or use a bank transfer. However, if you're paying in cash, make sure to declare the money at the customs office to avoid any trouble.

Now, let's move on to registering the car. This is where things can get a little frustrating. The first thing you'll need to do is get insurance for your car. You cannot register a car in Spain without insurance, so don't even bother trying. Once you have insurance, you'll need to go to the traffic department to register your car.

At the traffic department, you'll need to provide even more documentation. This includes the sales contract, proof of payment, your NIE, and your passport. You'll also need to pay a registration fee, which varies depending on the car's value. And yes, you guessed it, you'll need to wait in line at the bureaucracy office.

Once you've completed all the paperwork and paid all the fees, you'll finally receive your license plate and registration documents. Congratulations, you're now a proud owner of a car in Spain!

Now, let's talk about the humorous part of this whole process. You see, bureaucracy in Spain is a special kind of beast. It moves at its own pace, and you'll often find yourself waiting in line for hours on end. You'll need to bring a book or some kind of entertainment to keep yourself occupied.

And don't even get me started on the bureaucracy office workers. Some of them seem to take pleasure in making your life difficult. They'll nitpick every little detail on your paperwork, ask for documents you didn't even know existed, and make you feel like you're committing a crime just by trying to register your car.

But fear not, my dear foreigner friend. With a little patience, a good sense of humor, and a lot of determination, you'll be able to buy and register a car in Spain like a pro. Just remember to bring all the necessary documentation, have insurance, and be prepared to wait in line.

In conclusion, buying and registering a car in Spain as a foreigner is not that different from buying a car as a Spanish citizen. You'll need to provide certain documentation, pay fees, and wait in line. But with a little bit of patience and a good sense of humor, you'll be able to navigate the bureaucracy like a pro. So, go ahead and buy that car, my friend. The roads of Spain are waiting for you!