BMW North America issued 2 posters for dealers with M coupes on them. Both are 35.5 x 25.5 inches. The first poster “Dare to Be Different” is mostly black and the more common of them two. The second “Chili Pepper” is more rare. These do not have BMW part numbers, but they were sold to dealers as promotional items (the dealer actually had to pay for these) through Centernet for $5 each.
More rare than the two M coupe posters, there are two other BMW-issued posters with M coupes on them. The first is an M car celebration poster. It reads “A Legendary Heritage of Winning Performance by Design”. It is also 35.5 x 25.5 inches. Details at BMW CCA Foundation are here:
This one features an M1, E30 M3, E28 M5, E34 M5, E36 M3, and the E36/7 and E36/8.
Lastly, there was an anniversary poster produced for the 10th anniversary of the South Carolina BMW factory "Plant Ten". This poster had both an M and Z3 coupe on it. It’s also 35.5 x 25.5 inches.
There is a Z3 dealer poster I really like, which is "Happiness is not around the corner. Happiness is the corner".
Not E36/8, but equally cool, there was also a single MZ4 M Coupe E86 poster too. Also 35.5 x 25.5. “Wreaking serious havoc on the hierarchy of needs”. BMW CCA Foundation record is here: http://bmwcca.pastperfect-online.com/38856cgi/mweb.exe?request=record;id=ABF4197B-7CCC-463A-A2C9-805977428770;type=101
And lastly, I do have 1 copy of the uber-rare E90 M3 poster. This one is also 35.5 x 25.5, and it's double-sided. One side is the E90 M3 (Andy found the poster for me shortly before or after I bought my 2008 E90 M3 which is my daily "beater" car), the other side has an E92 M3.