The easiest way for that is to have the user set that position to account for the car model, driver height, and seat position, but you're not likely to find a w

The easiest way for that is to have the user set that position to account for the car model, driver height, and seat position, but you're not likely to find a way to pick a good safe spot to show it without asking the user. But if you say this is safe to use while driving, you need to handle situations where "this AR app had a bug which drew a solid color over the entire view, obstructing my view, and caused me to miss the pedestrian", while a projected HUD has a limited area it can draw on. If you can't/won't say it's safe to use while driving, then why develop the feature for driving? This being an eye piece which has software control over your entire field of view has potential for danger. Then you will have to make sure all of that doesn't replicate these results from the out set: https://arstechnica.com/cars/2015/07/heads-up-displays-in-cars-can-hinder-driver-safety/ https://arstechnica.com/cars/2015/07/heads-up-displays-in-ca...