My husband & I are interested in taking a private car service or a tour bus from Santiago to Mendoza (crossing the Andes). I understand crossing borders in rental cars is difficult if not impossible and this would be a one-way trip, so for logistical ease, we'd prefer to be driven and not drive ourselves. We are looking for a private car service or a bus tour, as opposed to public transportation, because we would like to stop along the way (& potentially learn something from the driver/guide). Our hotel does not know of any such services. Please respond if you have any recommendations. Thanks!