I picked this up on Amazon Amazon.com: Pyle Universal Vehicle Smart HUD Display - 2.6" Digital Mini Car Dashboard Heads Up Windshield Speedometer Projector System w/ GPS Navigation Compass, Displays Speed, Distance, Time and More - PHUD19 : Electronics There are others available, but this one was reasonably priced and easy to install. This might not be appreciated by purist, but I like not having to do the math. I placed it in a location where it doesn’t obstruct anything useful (unless you plan on exceeding 125KPH) It’s the second one that I have used. The first one is in a small electric car that I drive. I have found them to be accurate and durable. I plugged it into the accessory port (cigarette lighter?) in my Toyota truck and drove around for a couple of days as a test. It followed the digital speedometer in the truck just fine. I cut off the end of the cord and wired it into the bed light switch to the left of the steering wheel. It was easy access to a switched 12 Volt source. It has many functions, but only displays three. Obviously, I wanted the speed in MPH. Its also nice to be able to see the voltage on the 12 Volt source – you can see that you’re charging. And the clock is nice to have.
Once you get used to doing the math you hardly have to think twice about it. Cute gadget for people who are into that kind of thing.
I've been using that same unit for a little over a year now. Also got tired of doing math-on-the-fly since I only drive my truck maybe once a week, and I also wasn't sure how accurate my factory speedometer for its age.
