Not quite true. If a word ends in an r and the speaker is thinking about what to say next, he may in fact roll the r. Think about this sentence: "Estuvimos allí por... un rato." Often it'd be punctuated with ellipses, but in some sense it might be better written "Estuvimos allí porr un rato."

I've heard quite my share of Spanish and never happened upon that. Rather, people would extend the r without rolling it.

And in any event, that wouldn't mean there are words in Spanish with rolled final r's, which is what was being discussed, just that people might pronounce a word that way.

Argentinian here... and I'd usually extend the o, not the r, so "Estuvimos allí poor un rato."

Also, a lot of native spanish speakers pronounce all initial r's as rolled r's.

That's the way spanish is pronounced.

Radio is "Rradio".

I've found amusing how some people who learn english as a second language end up pronouncing spanish as "espanish", since no spanish word begis with s(consonant), except for sh.

"A lot" meaning all of them, because that's the norm.

nonsense.

Cite one?