pcons
M3 AWD+
for you in maryland it may not be an issue but for me in Vancouver it is a major issue. We get A LOT of rain here and in the winter my windows fog up a lot so I use the defroster to clear it away from the back window. When you combine the rain with shorter days it makes it hard enough at night to see out the back of window as it is, having a distorted view of what's happening behind me doesn't help the situation one bit.
In ideal condition it's really not a big deal but I'm trying to be proactive and not have to worry about this when the weather is bad.
Is your back window tinted? I ask because now that I've seen this thread I looked in the back of my volt on the way home and the road lines which nominally cross the defroster lines at 90 degrees also got distorted. The effect seemed to get worse the more oblique the light passing through the window was (ie, closer to the bottom).
I didn't take any pictures, but for fun I will try and get some. But I also have tints on, and I'm wondering what effect the tint film may play in this as well.
Also would be interested to hear what tesla has to say about it.