He says that there are two forms of "R", one as in "red" and the other as in "car". I've been sitting here reciting these to myself over and over, and I can't hear a difference. Neither can my wife, who has a degree in linguistics and speaks English and French fluently.
Just guessing, but in non-rhotic accents like RP and New Zealand English, the R in car is not pronounced unless the following word begins with a vowel. Any other ideas, maybe from an American English speaker?
For most American dialects, the sounds are nearly identical, but not quite: at the beginning of a syllable, the "r" is an approximant (a type of consonant that starts with an emphasized vowel sound), rather like "y" or "w", whereas at the end it is a true vowel, again like "ee" or "oo" respectively.
I'm a native en-gb speaker: I'd say the R in red is hard (ruh! like huh!) and the one in car is soft (aspirated; "ar") but I don't know IPA so couldn't really give you any more than this.
In New Zealand English, you should be comparing the pronunciation of R in “red” and “car audio”, to ensure that the R is actually pronounced at all. Some accents don’t even pronounce it in the latter. (There’s a good one for the spelling reformers.)
And be careful with “ah”. I have a strong suspicion that we pronounce it very differently in New Zealand compared to North America.
With my Australian accent I wouldn't pronounce an "r" sound in "car audio" either -- just switch straight from the "ahhh" sound of "car" to the "orrrr" sound of "audio".
Speaking of which, it wasn't until quite recently that I realised not all accents have so much trouble with the ambiguity of the Ford Ka.
Can someone explain the difference?