hey that ones gets most people the first time they drive the mk3 and use the rear wiper!

it gets better though...
the intermittent front windscreen wipe you can adjust
pull the stalk down to the intermittent wipe, let it wipe and then pull it back up
when the desired intermission between wipes has been reached pull the stalk back down to the intermittent wipe position
i think you can set the time anywhere between 2 and 8 seconds but play around with it
as soon as the ignition is switched off the set intermission time reverts to default