Windscreen wipers are so irritating.
Using windscreen wipers to get rid of dead insects results in the windscreen getting oily. The wipers just smear the oily substance and especially at night visibility is severely compromised. This is very inconvenient and sometimes outright dangerous.
The only way of dealing with this problem is to use the windscreen wash. However, many cars will wipe 3 or 4 times, wait 20 seconds and then wipe once more. Without windscreen wash, this last swipe is however just smearing the oily substance right back on the windscreen. Highly frustrating, especially as the driver has no possibility of turning this last "smear" off.
Rain sensors are way too sensitive! 3 drops of rain will activate the wipers on an almost dry screen. However, a driver has no possibility to sufficiently reduce the sensitivity. The result is that a driver regulates the wipers by hand which compromises road safety.
The old Skoda Favorit had a very efficient and cheap system. If you wanted to use the wipers intervalley, you would engage the wipers once, waited the required time (for instance 8 seconds) and engage once more. The car would now repeat your 8 second interval. No sensors needed, easy to use and always achieving the required result.
Obviously it would also be sufficient when car manufacturers would be forced to install windscreen wipers that allow for intervals between 1 and 20 seconds and an off-function for the "extra swipe".