score:8
Street food carts are mostly illegal under Hong Kong law. Technically, there are licenses for them. However, due to HK's rising standard of food sanitation, these licenses have de facto been phased out. You can find some of those carts in the New Territories, where the law isn't always strictly enforced (especially around universities late in the night, because, well, this is how college students eat). If you're lucky, you'll find a cart noodle (ce zai min 車仔面) cart or oil fried stuffed veggies (zin neong sam bo 煎釀三寶) cart somewhere in Tuen Mun, or perhaps in Sha Tin around the Chinese University. (These are my Hong Kong street food favorites, and are worth a try.)
Nevertheless, there are street-side "stalls" (or more aptly simple restaurants) in most busy areas. They usually have no seating and are not full fledged restaurants, but they're much more polished than "street food" you'd see in mainland China, for example.
There are numerous daipaidongs in Hong Kong. I remember of one in Sheung Wan serving pretty good food (although that one is indoors and doesn't quite have the "right" vibe). But then, to fully enjoy those places, you'd need to go with someone who speaks Cantonese.
Upvote:2
There are some daipaidong in Central, off Queen's Road. But street food is not a thing in HK. The weather doesn't help, of course, but it isn't something people do here now.
Most cheap food is served in restaurants, rather than on the street. Then again, there isn't much cheap on HK island anyway.