They won´t fit directly but it should be possible to change the mounting and plug. The rest seems to be similar.
300M-Mirrors electrical heated, e-adjustable with side-turnlights original



300M-Mirror on Neon door - the mounting is to small, has a different form and the 300M-Mirrors seem to be always painted








The housing and mirror seems to be the same.
Next time I will meet him again and we will try to cross the Neon and 300M Mirrors, because he likes to get the electric folding function on his 300M (which is available on uk-Neons), I like to get the turn signals on my Neon and he told, he succesfully disassembled the 300M Mirror totally a few months ago.