Here are my before and after locations.
I relocated to reclaim that much needed vent for the Winter while doing some other mods(a work in process).
I just have it above the dash and slightly to the right using their bracket, no photos.
I like it but I find that it over-estimates my fuel efficiency for city driving when there is a lot of cold starts. And in winter when it is quite cold (this morning about zero degrees F) the vehicle uses a lot more fuel during the warm up than the gauge indicates.
I think (but do not know for sure) that the gauge uses vehicle sensors to measure air flow into the engine, then uses a standard stoichiometric ratio to estimate fuel usage. But when it is cold the vehicle burns more fuel than the standard ratio.
I believe there is a menu option to adjust the fuel economy estimator, or i think i read that in the guide book.