Is there a proper direction for a crush washer?

I give you two sides of a crush washer for my BRZ transmission and diff drain plugs.

Is there a proper side to go towards the bolt and towards the trans or diff? 

I do not know the correct answer, but if it was me I would have the side on the left face the transmission and the one on the right facing the flange of the bolt if that makes sense. So groove against the transmission. 

In reply to Definitely gone now :

That was my guess. 

I also guessed it was most important just to use a new one each time.

I would guess flat side toward the transmission, especially if it is aluminum.  I would rather potentially put a grove into the bolt than the transmission.

I would also suspect, sealing wise, it won't matter.

Well I made my choice and went flat side to the nut. I did the same for all 4 bolts so we won't have a head to head comparo.

Pray for mojo
 

I don't know.  Never thought about it.

But, thinking about it now, since it doesn't seem obvious, I would put the groove toward the bolt, smooth toward the pan.  If the groove is going to score something, I'd rather replace the bolt than the pan.

But I don't know anything.  :-)

There is a TSB for certain years of 2.0 VWs about the drain plug leaking. It boils down to you have to use a crush washer like the one posted or it will leak, and from personal experience they are correct. Im almost positive they spec the grooved side face the pan. It is literally the only car or pan or plug of any sort Ive had this problem on, and have never paid attention to the way they go, and generally prefer copper washers, but since I ran into that If I get one like that I do groove in and havent had any problems.