There’s loads of traffic in Madrid and parking is yet another trial. In fact, most of the city’s touristy area isn’t even accessible by car.
If you decide to take the plunge, don’t park in the green areas because they are residents only, unless you park for an hour or less. Look for the blue areas, where you can pay and display at a machine for up to two hours. You also can park your car in the city's suburban areas and take the metro to the centre.