How would you write this in the phonetic alphabet?

It’s one word (a name), with three syllables pronounced as follows:
“Am” - just like the first person form of “to be”;
“buh” - short U sound;
“car” - as in a car.

Thanks.

Quick question regarding [“buh” - short U sound]:

Is that the “short u” American kids learn about in kindergarten & first grade? The vowel in General American (newsreader) “cup”, “sum”, “rough”, etc.?

Missed Edit window:

Or is “uh” meant to represent a schwa sound – such as in the unstressed “a” in “sofa” (General American)?

Also – which syllable is stressed?

Oh, sorry. It’s more of a schwa. It could just as easily be “bah”. The stress is on the B.

Stress is carried by the syllable – do you mean the “bah” syllable is stressed? If so, then a reasonable phonetic transcription could be:

/æmˈbəkɑr/

Actually, now that I think about it the stress is on the first syllable. I never really understood that stuff.

Alpha Mike Bravo Uniform Hotel Charlie Alpha Romeo

No, wait. Try here.

No worries, just a slight change:

/ˈæmbəkɑr/
From the perspective of us American English speakers, the broad strokes of stress are easy to grasp. All stress really means to us is that the syllable pronounced a little more loudly and “fully” – with a little more “oomph” (not a lot more, a little more :D) – is the stressed syllable in a given word. For example:

GENeral
CINammon

toMAto
inFLAtion

everyDAY (adj)
muscaTEL

Today we can reCORD a TV show. Teens in the 1960s played RECords.

And so forth.

Much obliged.

Alpha Mike Bravo Uniform Hotel Charlie Alpha Romeo… am I being woodshed?

Nah, the OP is asking for a rendering in a “phonetic alphabet” in the sense of an alphabet that shows the pronunciation of the word. The International Phonetic Alphabet is one of the best known of these.

Alpha, bravo, charlie, etc is a “spelling alphabet” in which words are spelled out in a code in which each individual letter is assigned a name, for clarity in transmission. But spellling alphabets, despite sometimes being called phonetic alphabets, tell you nothing about how words are pronounced.

Well, yes, but it “means” a little more to us than that. (And it’s not just American English–it’s all English.)

The vowel of an unstressed syllable becomes something quite distinct from its stressed from–usually it becomes /ə/ / or /ɪ/. One convenient demonstration of this comes about with the different forms of many Greek-origin words of the same root, such as:

photograph => photography
/ˈfoʊ təˌgræf/ => /fəˈtɒg rə fi/
The first vowel in photograph is /oʊ/, but in photography the first vowel is /ə/, and this is because of the change in syllable stress.

Everything you wrote is correct. I was merely bowdlerizing (a lot) for the sakeof making a broad point, since the OP expressed that he didn’t have much of a grasp on the concept of syllable stress.