Fuel I can understand, since it's nice to know if you need to stop for gas before work or something like that. Outside of that, I feel like it's just cool to be able to see.

I think I'd prefer a notification for Fuel Low or Car Maintenance Due, rather than always seeing the full information, but on the other hand, that isn't as cool, haha.

Sadly I have no recommendations on displays, but I'll go out on a limb and assume you won't want to go with e-ink for an accurate speedometer lol.

If you're trying to track such things, I could see it being more convenient to record indoors. I would prefer to have a notebook on my desk to write it in than to be writing things in the car on the steering wheel, for example.