Three ideas...
There is already a patent for side view mirror wipers... but I don't think they've ever seen mass production... there are heated side view mirrors... but when it is misty out or rainy, it can be tough to see out the side mirrors...
so route little air nozzles into the top part of the mirrors which blow air down the mirrors and clear off the condensation. Designing and powering a small compressor shouldn't be a big deal. And/Or you could high-tech things up a bit by coating the mirror surface with something that repels water.
2nd idea is home related... you are probably not a home owner, but an annoyance is having to clean out the gutters on your home. Sure, you can install gutter guards to keep leaves and debris out in the first place, but what often happens in the winter is the small holes in the gutter guard freeze over which prevents the melting snow on your roof from entering into the gutter... and you get ice dams.
My thought was use existing sources of heat to keep the gutter guards from freezing like the excess heat from the clothes dryer vent which is vented out to the open air anyway, or exhaust fans from bathrooms and the kitchen - all sources of wasted heat. Or high-tech it with a small solar or wind powered unit that heats a coil that is either impregnated into the gutter guard which would warm it up enough to prevent freeze over, or it heats a coil that is lain across the top of the gutter guard in the fall, then can be removed in the spring.
A third invention would a device to assist with removing your eyeglasses. It could be a curved piece that attatches to the bridge of the glasses, and have a pad on the other end that rests on your nose to prevent your glasses from slipping down. Call it opti-grab or something. Betcha you'd sell MILLIONS!