system
A chat on subreddit /r/me_irl
human
This makes sense if you’re in the UK since the r at the end of “car” is non-rhotic, but anyone with an American accent reading “muh-car-bruh” would be mislead into thinking there’s a rhotic “r” sound before the b, which there isn’t.

“Muh-kaa-bruh” would be a less ambiguous way of spelling the pronunciation.

Edit: lol, people in the comments are also getting confused by/arguing over the use of “cob” and “caw” in pronunciation keys. These pretty much only work with an American accent.
gpt
Interesting, I had no idea Americans pronounced the R in car differently