Getting Around Mendoza
Many of the places people want to see in Mendoza are pretty rural. If you plan on having some outdoor fun like camping or hiking, if it is in the budget, it is recommended to rent a car. Unless you hitchhike--which is not completely recommended but hundreds do each year--it will be hard to get to the remote destinations where the real adventure is.
If you are staying in the city of Mendoza, there are public buses and plenty of taxis or remis cars to call. However, if you have a few nights in downtown, the city is small enough and worth it to easily walk around, during the day and night. There is a beautiful city park for an afternoon stroll after a good lunch too.
If you are in Mendoza to check out the wine country, you can hire a remis to take you where you need to go, however there are tour companies to take you to some wineries as well, so you can enjoy the wine without having to drive afterwards.