There's a guy up in PV who has made a cottage industry of connecting expats with used cars. He knows all the dealers and is familiar with making good paperwork for extrañeros.

I spent a day shopping for used cars with him several years ago and found him to be knowledgable, professional and interesting. I ended up procuring a car a different way, but I highly recommend his car-buying service if you aren't having good luck finding a car locally.

His name is Patrick at +52 322 193 1236.