The more I read the more confused I am. What bulb is used for the back up lamps???
Most here reference the wedge style base 168/194 so I assumed that is what's used.
JCunningham mentioned 10351677 which looks like this

Doesn't look like a wedge base to me.
At the beginning of the thread someone shows how to cobble something together with silicone, I suspect to fit the strange base pictured.
Then to add to the confusion I looked up the bulb on the Sylvania site and they list something else.
I would just take out the bulb and check if I didn't have to take the rear end of the car off!
I could care less how the bulb "looks", I just want something bright enough that the back up camera actually shows something useful at night. Right now I think I get more light out of my brake lights than the back up lights.