Got one in the turbo. The car is a bit of an outlaw with a modified interior. The PO put it on the lower left ,near the ignition. It comes in handy and is comforting to see, BUT if I was choosing I'd likely get this one from Summit Racing. Not an exact match with the gauges, but pretty good for off the shelf.

https://static.summitracing.com/glob...4191-01_xl.jpg

In my 73 E I mounted into the cigarette lighter. Looked fine, was easily readable and was easily stashed in the glove box when not needed.

Fabed it from a cut off screwdriver handle that fit the cigarette lighter well and attached the other end to the gauge.

No permanent changes to the car.

Chris
73 E
89 Carrera

I use 2 in the 72mfi seems to work good