Dogging is a quite common activity in the UK, and has also been seen in some countries that have a big UK Ex-Pat population.
It got the name "Dogging" from people saying they were taking the dog for a walk, what they were actually doing is going to "lovers Lanes" and car parks to watch couples having sex in their cars. Initially they were peeping, not wanting to get caught by the couple in case they stopped. Now couples and singles arrange to meet in secluded car parks and an etiquette has formed on how to behave while performing, watching and joining in.