I bought a mechanical guage from NAPA for about $20. It fit without the adapter; the adapter that came with it adapted to American cars. It works just fine; the trick is finding a place to put it where you can see it and not drill new holes in your dash. I ended up putting it on the far left through existing holes using tie fasteners; it stays well without making any permanent alterations, but visibility is impaired if the steering wheel is in the wrong place.

When you put it in, I suggest putting a little gasket sealer on the sensor threads or you may get some coolant leaks. Just don't use anything that will permanently attach the sensor to the engine bloc.