I've made the Austin Homebrew Dos Equis kit twice now. It makes a very nice Vienna lager that is somewhere in between Dos Equis and Negra Modelo, though with a little less hop bitterness than I'd like. I've tweaked the kit a bit each time I've made it. Wyeast 2124 Bohemian Lager makes for a very malty beer while WLP940 Mexican Lager (if you can find it) makes for a dryer, crisper beer. I left out the supplied 4oz of maltodextrine each time, depending on control of mash temperatures to achieve the body I was looking for. The second version, with WLP940, fermented out to 1.006 and was just a little thin. The maltodextrine would have helped.
I also changed the hop schedule for the second version, going with 1.5oz Tettnang @ 60, .5oz Tettnang @ 20, and 1oz Spalt @ 7 minutes. The original recipe calls for 1.25oz Tettnang @ 60 and .25oz @ 15 minutes. The second version was much better.
As Yooper said, though, you have to have the capacity to ferment cold. I have a spare fridge in the garage. If I turn the thermostat all the way down it will hold about 48°, which is a little cooler than ideal but has worked reasonably well for the lagers I've made.
Chad