The ability to set custom reminders (based on miles or time) would be nice. For example you could set a “Tighten wheel nuts” message in 30 miles to remind yourself to tighten them. (Typically for areas where separate winter tires are used.) When you pass 30 miles after setting the reminder, the car will alert you to (in this example) tighten the wheel nuts.
I don’t know of any cars having this, although most modern cars have a counter to alert you when an oil change is due. I think it should be a relatively simple software programming issue.
(lightly edited by moderator)