Magic is the obvious solution. There's not even a need to explain then, it's easy to imagine magic being used for building tall buildings without magic being able to power a car.
If you use technology it's harder to make it logical. Of course you can just ignore logical. In that case it's probably better to not bother with any explanation, no explanations are better than wrong ones.
If it's supposed to be internally logical and consistent it's important to keep in mind the difference between technology that just appeard around the same time here on earth in western culture, and technology that really is connected. I.e. for cars you need combustion engines. When you have combustion engines, you can and will use them to power pretty much anything. No cars and steam train. No cars and sailships.
Combustion engines also provide the basic working principle of guns, however if chemistry is pretty much nonexistent, maybe noone figured out how to make powder yet.
This can work very well in a steampunky world, were invention are basically created by inventive (and a bit crazy) individualists, and where the scientific method is unkown. Because with the scientific method, people systematically start to figure out how things work, which makes missing areas of technology a lot less likely.
Electricity is somewhat of a problem, you need some decent knowledge of physics for really starting off electric technology, let alone neon lights. Probably better to go at least half the way with magic.
It's pretty much the same for all really modern technology (20th century and later) A computer for example requires extensive knowledge in so many areas of science that there's not a lot that can be missing. I.e. a world with computers but without radio communication or television or telephones makes no sense. Unless they conciously chose not to use radio waves etc..