hahaha. I was actually thinking of Laa and aarder when I wrote that and sat in front of my computer doing a really bad American accent, trying to see if the transitional r worked. And you're right, it didn't. Which makes me wonder if it isn't more a geographically bound thing, rather than one related to the English language in general.
Anyway, I've decided that the New Jersey accent is now my favourite American accent of them all.
http://www.youtube.com/watch?v=6vkTN4-GZQQ