Looks like @Hobbes nailed it right off with this answer. There are two Prop-M rovers on Mars. While Mars-2 crash-landed, Mars-3 landed and began transmitting. However, thanks to some excellent research by @called2voyage, we can see that because the rovers would not be deployed without explicit radio instruction, neither rovers were ever able to "rove" on Mars. Nevertheless it seems they are there, in some form or other.
I'll have to think of something harder for a puzzler next time.
I'll add this cute GIF and photo, both found at the Wikipedia article for Mars 3. According to the article, the rover was to remain attached by an umbilical to the lander, and do some local exploration while monitored and sometimes filmed by the lander.
above: GIF of how the Prop-M rover uses it's "skis" to walk. Linked here, from Giphy.
above: Mars Prop-M rover from here.