Vehicle: Car: Communication
External Gear & Rev Display   (+5)  [vote for, against]
Externally mounted Gear Ratio display and Tachometer

This would be mounted at the rear of a car and allow you to see how hard the car you are following is driving.
-- Mung, Feb 17 2001

Speedo Confusion
Less is More [reensure, May 24 2002]

OK...but, why?
-- Susen, Feb 17 2001

Is this so you can be sure that you are yelling at them for the right reasons? (i.e. "SHIFT YOU A-HOLE!!")
-- blahginger, Feb 18 2001

If you're close enough to read it, you have other problems.
-- badoingdoing, Feb 18 2001

Either it would make the car really ugly, or anyone close enough would be tailgating.
-- badoingdoing, Feb 20 2001

Or go all out with a status display indicating things like:
--Actual Vehicle speed
--Average Vehicle Speed
--Current MPG
--Engine RPM
--Total Mileage of Vehicle
--Vehicle Weight
--Age of Driver
--Miles/Days Since Last Accident
--Cell Phone In Use

Deluxe versions could add things like:
--Number of Passengers
--Price Paid for Vehicle
--Driver Credit Rating
--Odds of the Driver Suddenly Applying Brakes
--Insurance Limits of Liability
--Inventory of Armaments Carried by Driver
--Current Vehicle Use [business, commute, errand, date, pleasure driving]
-- bristolz, Feb 20 2001

Of course, that would take up a lot of space on the back of the car and would be hard to read, so instead it should be done using some sort of electronic beacon. This could be easier than it sounds: your everyday LED can be modulated at pretty high speeds (megabits/sec), and most taillights these days are made out of LEDs, so the car could simply invisibly modulate this information into the car's taillights. (During the day, you'd only have this information while the car was braking --- a disadvantage.) Your car would pick up these data bursts and display them on its heads-up-display. An additional advantage is that you could customize the display to your own preferences, showing only the items you want.

Additions to bristolz' list:
-- number of hours since driver slept (and for how long).
-- state of other passengers (noisy kids? ex-driving-instructor uncle? distracting boyfriend?)
-- planned upcoming turns (this could be combined with the "Parking Light" idea)
-- random user-settable text fields, to be displayed on your HUD like a bumper sticker

-- wiml, Feb 20 2001

Apologies for my lacking elaboration. It would just be fun to compare your own cars performance to that of the person you are following/racing. Surely it would reduce the boredom of every day driving and allow you to impress other road users with your ability to drive your car right at it's limits.
-- Mung, Feb 21 2001

I suspect that most people would not know or care enough to be impressed with how you drive....and the people who do know enough are probably too busy being impressed with their own driving ability.
-- blahginger, Feb 21 2001

"and the people who do know enough are probably too busy being impressed with their own driving ability."

Exactly. Imagine the fun.
-- Mung, Feb 21 2001

If your close enough to read it, why not really impress yourself, drive a little closer still and read the dashboard directly?
-- ArtPrior, May 24 2002

-- yamahito, May 24 2002

Useful for the schmoe behind me when I downshift to enter a turn (or otherwise desire to decelerate quickly without using the brakes).
-- phoenix, May 24 2002

I'd rather my automatic transmission would just register its engaged gear on a dashbox digital display -- then I'd know if smoking along behind someone is bouncing me from 2nd gear to 3rd gear repetitively.
-- reensure, May 24 2002

Y'know, it'd be easier to just mount a huge price sticker on the back of your car... imagine, then you'd know for sure whether the person has a reason to be driving like an idiot!
-- Crazy Bastard, May 25 2002

I think a "penis length" indicator would be neat. I could then test my PL = 1/TS theory.

PL = Penis Length TS = Truck Size
-- rapid transit, May 19 2003

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