I think that I am ok, but not amazing, at rolling rs if they begin a syllable (onset). (For example maybe "red".)
However if the r is what ends a syllable (coda) (for example maybe "emperor or imperator") I fail miserably.
Also, it seems that I attempt to pronounce those r's without voicing (so sometimes my voicing cuts off in the middle of pronuncing a word)
Am I rolling my r's wrong?