Didn't work with a car that it should have worked on.
Says it works on cars 2004 and later with OBD2 but doesn't list exceptions. Didn't work beyond showing voltage on my 2004 Pontiac Grand Prix (with OBD2), which after a lot of digging elsewhereI found mean it doesn't work with my car. Not worth the postage to return it but seller definitely needs to provide a list of incompatible vehicles.
Great product at an incredible price. Just plug it in lay it on the dash and stick the cling film to the windshield and it works. I had to adjust it down 2 mph ( an easy push in and turn the wheel). I have bought one for each of my cars. No struggling to read the speedometer in bright lighting anymore.