[Obviously very low priority, and probably even impossible to make]
Every singe car has a number which is useful for identifying the vehicle. It would be nice to have the possibility to give a name to your car, maybe through dialogue ("Say" option), while buying it, so only the one who buys it can name it.
This way, to identify a car you don't need to use Science on it. If you move your mouse over the car, you would get a message like "you see: Buggy/Hummer/whatever", but if you Examined it, you would a message similar to "You see [car name]"
The same would happen with Car Keys.
Edit: yeah we would get a lot of stupid names, but we already got that with char names, which is worse.