According to the article 18 of the Traffic Law of Spain – the driver is obliged to drive a vehicle with comfortable clothes and shoes. It is forbidden to wear clothing or shoes that would impede his/her free movement, limit his/her movements or create a hazard during the driving.
Wearing flip flops, slippers, or any type of open summer shoes that can cause slippering the shoe or the driver’s foot on the pedal, or even the hitch in the vehicle’s pedal, is forbidden.
If the traffic police stop you and finds that your clothes does not comply with the Spanish Road Traffic Law, you may be fined EUR 80.
It is also forbidden to drive a vehicle with headphones (on your ears) connected to any sound devices or receivers.
If the passenger onthe front seat, next to the driver, has got his feet on the dashboard or has shown them through the window of the car, the driver risk to be fined with € 100.