Is there any way using scripting and command markers to set up a scenario thus:
A particular vehicle type appears on screen, and using a "Mouse over" on that part of the image, an overlay pops up showing details of the vehicle.
This is used a lot in Amazon's "The Grand Tour" (The New Top Gear). I accept only in streaming could this be applied, but I don't have enough scripting knowledge as yet to a) see if it can be done or b) if so,do it.
Whatever it is, it is proprietary to the platform you are using so I don't see how it could be automated. For example, YouTube annotations must be created in their own on-line video editor so that would be impossible to add automatically unless you used a keystroke recorder and playback. I don't know what Amazon uses but again, it's probably proprietary so there is no way to pass that information in with your video.
The old Windows Media Video (WMV) format had a way to imbedding markers that Vegas Pro supports but that is an outdated technology that doesn't work on the majority of Internet browsing devices (i.e., smart phones and tablets) and even YouTube Annotations don't work on smart phones so there really isn't any reliable way to accomplish this that I can see.
Besides, "hover" is a desktop concept. There is no concept of "hover" on a smartphone or tablet so you would not want to incorporate that into any "future thinking" design for Internet video because most people would never be able to use it. You would have to guarantee that your users would only be watching your video on a desktop computer for it to work.