Along with such taxis for tourists, there is a cheaper taxi service used by locals to get from one district to another, called “conch cars” (which follow a designated letter-assigned route, such as “Route A”, “Route M”, etc.).  In fact, to get from one far-flung district to another, one may have to take at least two separate “conch car” routes because they are fixed to a designated route.  Tourists can avoid dealing with this by simply looking for a “conch car” that has no passengers and negotiate a reasonable sum to take you when you need to go directly (without the driving picking up passengers in the process).  For those renting a car, there are plenty of car rentals agencies in the Santiago area.