While not especially prevalent, the microwave powered by your car's cigarette lighter plug-in is both so awesome and so obviously a bad idea that this list would simply be incomplete without it. With so many commuters stuck in traffic and trying to multitask on the way to work, a surprising number of manufacturers have jumped into mini-microwave creation [source: Houston].
In fact, the mini microwave of death is but one in a category of dangerous in-car appliances that allow you to do things in your vehicle that you really should have done at home, including refrigerators, popcorn poppers, Wi-Fi routers, a range of personal grooming equipment and, of course, coffee makers. Your car should be for getting you from place to place, not for preparing meals and going through your daily getting-ready-for-work routine.
Though not technically an in-car accessory, some have even tried the addition of an under-car deep fryer, which also seems like a recipe for disaster.