Yes, I am. Do you have a problem with that? What do you care how, when or if I ever use the thing?
If I want to know exactly how much time difference there is at different speeds, I can find out -- either at some point when I'm not driving, or at my discretion at some point when I can, safely, partially divert my eyes from the road for a few seconds. No need to either pull off the road, or spend any significant amount of time fiddling with it.
If my passenger wants to know, he or she can bloody well figure it out for his or her self, and it will likely take them longer. They'll have a fairly precise answer to their question.
Neither of these conflict in any way with anything I said earlier. You seem to be either making some deeply flawed assumptions about things I have not said, or just trying to invent scenarios where you're right and I'm wrong. Good luck with that. If I want to toss an E6B, calculator, pliers, tire pressure gauge, tuning fork, sun dial, soldering iron, condoms, .45 automatic, alarm clock, compass or a box of flippin' pipe cleaners in the glove box, I'll do so and use or not use them as I see fit.