Specifically, would it be plausible to have someone whose say, 17, to already know how to do performance modifications and the like on a car? I'm specifically thinking of someone who could work, but can't for age reasons, in a car tuning shop, like Mugen, or Hennessey except way, way lower scale. I'm sorry if this sounds like a ridiculous question, either way, but I don't know much about car culture, much less about car tuning shops like this. I didn't even know about either Mugen or Hennessey until like, a few months ago at the earliest. I was vaguely aware performance shops were something that existed, but didn't realize how large scale they could get. I'm assuming there are much smaller scale versions of that, and so... Well, in relationship to a book I'm in the early stages of writing, is it plausible for someone relatively young to already have enough knowledge to do some performance tuning themselves? I'm writing this because, for story reasons, I'm looking to write a character whose relatively young, but can also do lots of vehicle modification for plot purposes. More on what the culture and commonality of these performance/tuning/what have you shops would also be appreciated. Sorry if any of this is stupid/ridiculous/what have you.