When I did that, an Avis comes up, but I'm not convinced it's really there. I live in ABQ and while I don't go downtown very much (where the Amtrak station is), I don't remember seeing any car rental agencies in that area, but that doesn't mean that there aren't any. I would definitely call before relying on Google maps or the like. However, one nice thing about the train station is that it is next to the transit hub for Albuquerque city bus system, so there are a lot of buses one can take from there to different parts of the city. Furthermore, Amtrak shares space with Greyhound at the station and the RailRunner train also stops there. The Railrunner goes from Belen (south of ABQ) to Santa Fe with several stops during its run and several runs a day.