i can't tell from the video (had the sound down so as not to dusturb my wife) but the antenna appears to be a quarter-wave. with a magnetic base it is designed to use the metal roof of a vehicle for the ground plane. it works..but not as well as it could just like my dual-band glass mount antenna works on the 2-meter and 440 amateur bands....just ok.
i didn't do a ton of research but the websites i did look at suggest that radios used in mexico need to be certified for use in mexico and those radios use the Family Radio Service (FRS) frequencies and not the GMRS frequencies.
https://www.qsl.net/wd9ewk/xe-frs.htmlgood luck and be careful.