I don't know about you guys but my handheld karcher has a short power cord. This means I need to move the unit around with one hand, the lance in the other, and have a long trail of power cord and hosepipe around the car. Very frustrating, especially with the tangling.
You can buy an official Karcher 6m hose extension. For £35-45 (depending on the reseller).
Or for £15, you can buy this:
clickyConnects just fine and no problems with it so far. The Karcher unit stays in the garage with the power cord and hosepipe far apart whilst you walk around with just a lance.
Makes life so much easier.