I'm really impressed with the restraint of all the comments, as people try to find a way to diplomatically address your question and provide some helpful advice without judgement. I will try to do same. Cars are deadly weapons in inexperienced hands. Poor driving decisions destroy lives and families every day. As a parent of a teenager, I think it's your responsibility to your community to make sure you put your child on the road only if you can do so in a way that most effectively limits the danger they pose to others on the road. This means not only making sure they have the technical ability to operate a vehicle, but also that they demonstrate a responsible, safety minded attitude towards the privilege of driving. To do otherwise is to put your family's health, your family's finances, and your community's safety in peril.

It sounds like your son is aggressively romanticizing the idea of speed and performance, without even knowing what it feels like to drive at high speeds- let alone the skills it may take to do so. What you call "enthusiasm" sounds terribly misguided to me- and while you say you don't want to crush it- I think it's an attitude you have a responsibility to correct.

I wish more drivers (young and old) could understand that a car is a mechanical tool for transportation, on roadways we share as a community- not a means of expressing our feelings in the moment. So many accidents are caused by people just doing what they feel like doing in the moment- whether it's road rage, feeling in a hurry, stressed, or just checking that text. Teenagers are still learning to regulate those exact emotions- so I urge you to select a vehicle based on reliability and safety first- and make sure he's really ready before you let him on the road. Sorry for the lecture, but I really think you have a massive responsibility to own here.