I think your best bet would be to find a fairly simple to read meter of a size to fit where you want to put it, and is lit up. In a mobile, that 'size' thing will be the determining factor probably. One way of making that 'size' smaller is to use one of the 'cross-needle' meters. They are also simpler to read once you become accustomed to them, which doesn't take long at all. The 'best' thing about them is there are no calibration adjustments. Maybe a range scale, but that's it.
There are a number of manufacturers that make them, pick the one you like the best and can afford.
- 'Doc