As noted under advantages, a rental car can be budget friendly transportation. However with only one or two people, you’ll pay more for the convenience. A four-wheel-drive sport utility vehicle isn’t absolutely necessary, but there are many places you can’t get without one, and they survive the battering of the huge potholes on the paved roads much better.
A mid-size SUV costs around $US 60-75 per day, plus gas (typically double the U.S. price – for example ¢625 per liter or ~$US 5.60 per gallon in mid 2015) and insurance ($US 12-18 per day), plus a 12% airport concourse fee if you pick it up there. Don’t forget that you will be paying for the car every day, so three days of hanging out on a beach will cost you at least $US 200 for your parked car.
One way rentals are possible but surcharges for drop-off at your destination tend to be expensive.
The biggest inconvenience experienced by most renters is the complete lack of respect for customers that has become the standard culture at the rental agencies. At least half the times we rented a vehicle there have been hidden charges, fake taxes added, no car when we arrive with a reservation (and once it took two days…), the wrong car (“sorry I understand your reservation was for a 7 passenger SUV but you’ll either have to strap your luggage to the roof of this compact car and all cram in or head to the bus station”), $200 car wash charge (fought that and got it dropped) or some other scam.
We’re not the only ones. Just take a look at tripadvisor. It’s epidemic, present in every agency from the big international chains to the small local companies, and they simply have no incentive to change. There are more renters than cars so they’re not afraid of losing business and you have to return home at the end of your trip making it very difficult to fight any unfair charges.
On the tourist trail theft from parked cars is epidemic. You must remove everything each time you stop, leave someone with the car constantly, or hire someone to watch it. It is ill advised to park even an empty car outside a secure lot overnight.
Getting lost can be an adventure or an inconvenience. You won’t really be sure until you try it, but pilots and bus conductors rarely lose their way.
There are places like Tortuguero that you can’t access by road even if you go buy a Humvee. Other places travelers without a car have fun options like a boat ride across Lake Arenal then Horseback to Monteverde while those with a car are stuck driving 4 hours.
If you’re not experienced driving narrow, winding mountain roads with no guard rails and facing oncoming loco drivers passing on a curve then you might be better off leaving the driving to someone who is and traveling in a good sized mini-bus instead of a little economy car.
A car insulates you from the people, culture and wilderness. You won’t meet fellow travelers or people along the way, and it’s unlikely that you’ll notice the column of leaf cutter ants marching alongside the road.