Difference in 1990 side mirror vs. 91 & 92

While I was taking apart a blue gray storm driver side door mirror, I did notice something. I’m fortunate to have M30s of 1990, 91, and 92 sitting at my house. The blue gray storm was from a 1990 model, the spare I had was from a 92 I believe. I noticed the bottom mount bracket had only 2 holes, whereas the bracket from the 92 had 3. I checked the 1991 model, and it had 3 as well. I wonder why the first gen (1990) M30 didn’t utilize the middle hole? It certainly looks like it helps with reinforcing the structure… it’s probably why it broke in the first place!



the orange is from a 92, the blue is from 1990. early models werent as rigid, only 2 bolt holes.

It looks like the guts are the same, but for 1990… the middle screw isn’t used.