Absolutely not, with how many other things use right click. A simple missclick would throw you out of the minecart, which is bad.I don't know if this is a bug or a lack of a feature, but I think it would be nice if you could do this, especially since you can right-click to get in one.
yeah, that's how you're supposed to dismountcan't you just hit the mount button to dismount a minecart already