Badly Designed Product:
Automatic door(both sliding and opening)
Sliding:
The automatic door is a bad design as it does not always open, even when you are standing right in front of it. Furthermore, the sensor does not sense that there is a person in between the doors and will proceed to shut the doors, which can lead to accidents.

Flinging Open:
The door does not have stickers or signs to tell you which way the door is going to open or it may have signs but are too small for a person to read them before it(door) crashes into them.
Lolz
Images from:
http://www.google.com/imgres?imgurl=http://precisionhighspeeddoors.com/images/sliding-automatic-door-for-commercial-buildings.jpg%3F799%2522&imgrefurl=http://precisionhighspeeddoors.com/services_4.html&usg=__gCY6BD7RrWSeJhn65tw4A0pvG0A=&h=300&w=297&sz=23&hl=en&start=0&zoom=1&tbnid=m08q9V57pC9K7M:&tbnh=143&tbnw=151&ei=OJVQTZL2OYq8rAfns4GOCA&prev=/images%3Fq%3Dautomatic%2Bdoor%26um%3D1%26hl%3Den%26client%3Dsafari%26sa%3DN%26rls%3Den%26biw%3D1278%26bih%3D607%26tbs%3Disch:1&um=1&itbs=1&iact=hc&vpx=899&vpy=107&dur=2008&hovh=226&hovw=223&tx=109&ty=133&oei=OJVQTZL2OYq8rAfns4GOCA&esq=1&page=1&ndsp=18&ved=1t:429,r:4,s:0
and....
http://www.google.com/imgres?imgurl=http://www.liautomaticdoors.com/images/doors/horton21.jpg&imgrefurl=http://www.liautomaticdoors.com/horton_swing_doors.htm&usg=__6nKsuo9IyitB6OFijRWofzW7MJg=&h=333&w=427&sz=33&hl=en&start=0&zoom=1&tbnid=m4HncHfugfuL5M:&tbnh=137&tbnw=173&ei=15dQTc6ACI_prQeE7ImOCA&prev=/images%3Fq%3DAutomatic%2BSwinging%2BDoors%26um%3D1%26hl%3Den%26client%3Dsafari%26sa%3DN%26rls%3Den%26biw%3D1278%26bih%3D607%26tbs%3Disch:10%2C154&um=1&itbs=1&iact=hc&vpx=829&vpy=262&dur=2078&hovh=198&hovw=254&tx=160&ty=123&oei=15dQTc6ACI_prQeE7ImOCA&esq=1&page=1&ndsp=19&ved=1t:429,r:17,s:0&biw=1278&bih=607
