FYI, there's a ton of these Chinese/Hong Kong complete radio replacements for Mazdas, various models. They're cool, but the software SUCKS. The nav is and probably worse than the TomTom too. Usually these head units run a custom Windows Mobile 6.x and also uses TomTom but a pirated/hacked version.
I had one of the first ones on my 1st year 2004 Mazda 3.